U.S. patent application number 12/558423 was filed with the patent office on 2010-01-07 for tissue visualization and manipulation systems.
This patent application is currently assigned to Voyage Medical, Inc.. Invention is credited to Vahid SAADAT.
Application Number | 20100004506 12/558423 |
Document ID | / |
Family ID | 46327512 |
Filed Date | 2010-01-07 |
United States Patent
Application |
20100004506 |
Kind Code |
A1 |
SAADAT; Vahid |
January 7, 2010 |
TISSUE VISUALIZATION AND MANIPULATION SYSTEMS
Abstract
Tissue visualization and manipulation systems are described
herein. Such a system may include a deployment catheter and an
attached imaging hood deployable into an expanded configuration. In
use, the imaging hood is placed against or adjacent to a region of
tissue to be imaged in a body lumen that is normally filled with an
opaque bodily fluid such as blood. A translucent or transparent
fluid, such as saline, can be pumped into the imaging hood until
the fluid displaces any blood, thereby leaving a clear region of
tissue to be imaged via an imaging element in the deployment
catheter. Additionally, any number of therapeutic tools can also be
passed through the deployment catheter and into the imaging hood
for treating the tissue region of interest.
Inventors: |
SAADAT; Vahid; (Atherton,
CA) |
Correspondence
Address: |
LEVINE BAGADE HAN LLP
2400 GENG ROAD, SUITE 120
PALO ALTO
CA
94303
US
|
Assignee: |
Voyage Medical, Inc.
Campbell
CA
|
Family ID: |
46327512 |
Appl. No.: |
12/558423 |
Filed: |
September 11, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11687597 |
Mar 16, 2007 |
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12558423 |
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11259498 |
Oct 25, 2005 |
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11687597 |
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60783494 |
Mar 17, 2006 |
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60649246 |
Feb 2, 2005 |
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Current U.S.
Class: |
600/109 ;
600/156 |
Current CPC
Class: |
A61B 1/00082 20130101;
A61B 1/015 20130101; A61B 1/04 20130101; A61B 8/12 20130101; A61B
5/6882 20130101; A61B 1/00089 20130101; A61B 8/445 20130101; A61B
2018/0212 20130101; A61B 1/00085 20130101; A61B 1/0008 20130101;
A61B 5/02007 20130101; A61B 5/0031 20130101; A61B 1/018 20130101;
A61B 1/005 20130101 |
Class at
Publication: |
600/109 ;
600/156 |
International
Class: |
A61B 1/04 20060101
A61B001/04; A61B 1/12 20060101 A61B001/12 |
Claims
1. A method for accessing a tissue opening, comprising:
intravascularly advancing a deployment catheter within a chamber of
a heart filled with blood; reconfiguring a barrier or membrane
projecting from the deployment catheter within the chamber from a
delivery configuration to a deployed configuration which defines an
open field; positioning the barrier or membrane over or upon a
valve such that the valve is bounded at least in part within the
open field; and, extending an elongate bypass member from the
catheter and through the valve such that a distal end of the bypass
member projects past the valve.
2. The method of claim 1 further comprising introducing a
transparent fluid into the open field such that blood is displaced
from the valve.
3. The method of claim 2 further comprising visualizing the valve
through the transparent fluid.
4. The method of claim 1 further comprising shunting blood through
the bypass member from a first region proximal to the valve to a
second region distal to the valve.
5. The method of claim 4 wherein shunting blood comprises passing
the blood through at least one opening defined along the catheter
proximal to the barrier or member and through at least one opening
defined at or along a distal end of the bypass member.
6. The method of claim 4 wherein shunting blood further comprises
controlling a direction of the blood flow via a one-way valve.
7. The method of claim 1 further comprising deploying a support
flap from a low-profile shape to a deployed shape distal to the
valve.
8. The method of claim 1 further comprising treating the valve
bounded at least in part within the open field.
9. The method of claim 8 wherein treating comprises treating a
mitral valve.
10. The method of claim 1 wherein intravascularly advancing the
barrier or membrane comprises advancing the deployment catheter
intravascularly into a left atrial chamber of the heart.
11. The method of claim 1 wherein reconfiguring comprises deploying
the barrier or membrane into a conical structure which defines the
open field.
12. A valve tissue treatment system, comprising: a deployment
catheter having a barrier or membrane projecting from a distal end
of the catheter, the barrier or membrane being reconfigurable
between a delivery configuration and a deployed configuration which
defines an open field; and, an elongate bypass member which is
translatable through the open field and beyond the barrier or
membrane, wherein an opening defined near or at a distal end of the
bypass member is in fluid communication through the bypass member
with one or more openings defined along the catheter proximal to
the barrier or membrane.
13. The system of claim 12 wherein the open field is sized for
placement over or upon a valve positioned within a heart.
14. The system of claim 12 further comprising at least one imaging
element positioned within or along the barrier or membrane for
visualizing within the open field.
15. The system of claim 12 wherein the bypass member further
comprises a tissue attachment member.
16. The system of claim 12 wherein the barrier or membrane forms a
conical shape in its deployed configuration.
17. The system of claim 16 wherein the barrier or membrane forms a
conical shape which is off-center relative to the catheter.
18. The system of claim 12 further comprising a fluid reservoir in
communication through the catheter with the open field.
19. The system of claim 12 further comprising a one-way valve
within the catheter or bypass member for controlling a direction of
flow therethrough.
20. The system of claim 12 further comprising a support flap
attached to the bypass member and deployable from a low-profile
shape to a deployed shape distal to the barrier or membrane.
21. The system of claim 12 further comprising an instrument
deliverable through the catheter and into the open field.
22. A method for imaging a tissue region, comprising:
intravascularly advancing a deployment catheter within a chamber of
a heart filled with blood; reconfiguring a barrier or membrane
projecting from the deployment catheter within the chamber from a
delivery configuration to a deployed configuration which defines an
open field; positioning the barrier or membrane adjacent to or
against an annulus of a valve to be visualized such that a portion
of the annulus is bounded within the open field; introducing a
transparent fluid into the open field such that blood is displaced
therefrom; and visualizing the portion of the annulus through the
transparent fluid.
23. The method of claim 22 wherein intravascularly advancing the
barrier or membrane comprises advancing the deployment catheter
intravascularly into a left atrial chamber of the heart.
24. The method of claim 22 wherein reconfiguring comprises
deploying the barrier or membrane into a conical structure which
defines the open field.
25. The method of claim 22 wherein positioning comprises steering
the deployment catheter within the chamber to the annulus.
26. The method of claim 22 wherein introducing comprises pumping
the transparent fluid into the open field through a fluid delivery
lumen defined through the deployment catheter.
27. The method of claim 22 wherein introducing comprises pumping
saline, plasma, water, or perfluorinated liquid into the barrier or
membrane.
28. The method of claim 22 wherein visualizing comprises wirelessly
transmitting data received from the portion of the annulus.
29. The method of claim 22 wherein visualizing comprises
illuminating the portion of the annulus.
30. The method of claim 22 wherein visualizing comprises recording
an image of the portion of the annulus.
31. The method of claim 22 further comprising repositioning the
barrier or membrane along a second portion of the annulus to be
visualized.
32. The method of claim 22 further comprising treating the portion
of the annulus with a therapeutic tool advanced through the
deployment catheter.
33. The method of claim 22 further comprising sensing a physical
parameter within or outside the barrier or membrane.
34. The method of claim 22 further comprising deploying an
anchoring assembly into the portion of the annulus.
35. A method for imaging an annulus of a mitral valve, comprising:
intravascularly advancing a deployment catheter within a left
atrial chamber of a heart filled with blood; deploying a barrier or
membrane projecting from the deployment catheter from a low-profile
configuration to an expanded configuration; positioning an open
field defined by the barrier or membrane adjacent to or against a
portion of an annulus of a mitral valve such that the portion is
bounded within the open field; and displacing blood from the open
field via a transparent fluid introduced through the deployment
catheter.
36. The method of claim 35 further comprising visualizing the
portion of the annulus through the transparent fluid.
37. The method of claim 36 wherein visualizing comprises wirelessly
transmitting data received from the portion of the annulus.
38. The method of claim 35 wherein intravascularly advancing the
barrier or membrane comprises advancing the deployment catheter
transseptally into the left atrial chamber.
39. The method of claim 35 wherein deploying comprises deploying
the barrier or membrane into a conical structure which defines the
open field.
40. The method of claim 35 wherein positioning comprises steering
the deployment catheter within the chamber to the annulus.
41. The method of claim 35 wherein displacing comprises pumping the
transparent fluid into the open field through a fluid delivery
lumen defined through the deployment catheter.
42. The method of claim 35 further comprising repositioning the
barrier or membrane along a second portion of the annulus to be
visualized.
43. The method of claim 35 further comprising treating the portion
of the annulus with a therapeutic tool advanced through the
deployment catheter.
44. The method of claim 35 further comprising sensing a physical
parameter within or outside the barrier or membrane.
45. The method of claim 35 further comprising deploying an
anchoring assembly into the portion of the annulus.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/687,597 filed Mar. 16, 2007, which claims
the benefit of priority to U.S. Provisional Patent Application Ser.
No. 60/783,494 filed Mar. 17, 2006 and is a continuation-in-part of
U.S. patent application Ser. No. 11/259,498 filed Oct. 25, 2005
which claims the benefit of priority to U.S. Provisional Patent
Application Ser. No. 60/649,246 filed Feb. 2, 2005, each of which
is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to medical devices
used for visualizing and/or manipulating regions of tissue within a
body. More particularly, the present invention relates to apparatus
and methods for visualizing and/or manipulating tissue regions
within a body lumen, e.g., tissue surrounding or adjacent to valves
within a heart, which are generally difficult to image because of
surrounding opaque bodily fluids such as blood or the tissue of the
inter-atrial septum for trans-septal procedures. However, it is
understood that the systems described herein may be used in various
parts of the anatomy.
BACKGROUND OF THE INVENTION
[0003] Conventional devices for visualizing interior regions of a
body lumen are known. For example, ultrasound devices have been
used to produce images from within a body in vivo. Ultrasound has
been used both with and without contrast agents, which typically
enhance ultrasound-derived images.
[0004] Other conventional methods have utilized catheters or probes
having position sensors deployed within the body lumen, such as the
interior of a cardiac chamber. These types of positional sensors
are typically used to determine the movement of a cardiac tissue
surface or the electrical activity within the cardiac tissue. When
a sufficient number of points have been sampled by the sensors, a
"map" of the cardiac tissue may be generated.
[0005] Another conventional device utilizes an inflatable balloon
which is typically introduced intravascularly in a deflated state
and then inflated against the tissue region to be examined. Imaging
is typically accomplished by an optical fiber or other apparatus
such as electronic chips for viewing the tissue through the
membrane(s) of the inflated balloon. Moreover, the balloon must
generally be inflated for imaging. Other conventional balloons
utilize a cavity or depression formed at a distal end of the
inflated balloon. This cavity or depression is pressed against the
tissue to be examined and is flushed with a clear fluid to provide
a clear pathway through the blood. Imaging may also use a
fluorescence or gamma adapted visualization elements. Such elements
may be able to distinguish between healthy and diseased tissue
(e.g., infracted heart tissue).
[0006] However, such imaging balloons have many inherent
disadvantages. For instance, such balloons generally require that
the balloon be inflated to a relatively large size which may
undesirably displace surrounding tissue and interfere with fine
positioning of the imaging system against the tissue. Moreover, the
working area created by such inflatable balloons are generally
cramped and limited in size. Furthermore, inflated balloons may be
susceptible to pressure changes in the surrounding fluid. For
example, if the environment surrounding the inflated balloon
undergoes pressure changes, e.g., during systolic and diastolic
pressure cycles in a beating heart, the constant pressure change
may affect the inflated balloon volume and its positioning to
produce unsteady or undesirable conditions for optimal tissue
imaging.
[0007] Accordingly, these types of imaging modalities are generally
unable to provide desirable images useful for sufficient diagnosis
and therapy of the endoluminal structure, due in part to factors
such as dynamic forces generated by the natural movement of the
heart. Moreover, anatomic structures within the body can occlude or
obstruct the image acquisition process. Also, the presence and
movement of opaque bodily fluids such as blood generally make in
vivo imaging of tissue regions within the heart difficult.
[0008] Other external imaging modalities are also conventionally
utilized. For example, computed tomography (CT) and magnetic
resonance imaging (MRI) are typical modalities which are widely
used to obtain images of body lumens such as the interior chambers
of the heart. However, such imaging modalities fail to provide
real-time imaging for intra-operative therapeutic procedures.
Fluoroscopic imaging, for instance, is widely used to identify
anatomic landmarks within the heart and other regions of the body.
However, fluoroscopy fails to provide an accurate image of the
tissue quality or surface and also fails to provide for
instrumentation for performing tissue manipulation or other
therapeutic procedures upon the visualized tissue regions. In
addition, fluoroscopy provides a shadow of the intervening tissue
onto a plate or sensor when it may be desirable to view the
intraluminal surface of the tissue to diagnose pathologies or to
perform some form of therapy on it.
[0009] Thus, a tissue imaging system which is able to provide
real-time in vivo images of tissue regions within body lumens such
as the heart through opaque media such as blood and which also
provide instruments for therapeutic procedures upon the visualized
tissue are desirable.
BRIEF SUMMARY OF THE INVENTION
[0010] A tissue imaging and manipulation apparatus that may be
utilized for procedures within a body lumen, such as the heart, in
which visualization of the surrounding tissue is made difficult, if
not impossible, by medium contained within the lumen such as blood,
is described below. Generally, such a tissue imaging and
manipulation apparatus comprises an optional delivery catheter or
sheath through which a deployment catheter and imaging hood may be
advanced for placement against or adjacent to the tissue to be
imaged.
[0011] The deployment catheter may define a fluid delivery lumen
therethrough as well as an imaging lumen within which an optical
imaging fiber or assembly may be disposed for imaging tissue. In
addition, the deployment catheter may have additional lumens for
various functions. For example, additional lumens may allow
aspiration of air bubbles or other substances that may interfere
with visualization of the target tissue When deployed, the imaging
hood may be expanded into any number of shapes, e.g., cylindrical,
conical as shown, semi-spherical, etc., provided that an open area
or field is defined by the imaging hood. The open area is the area
within which the tissue region of interest may be imaged. The
imaging hood may also define an atraumatic contact lip or edge for
placement or abutment against the tissue region of interest.
Moreover, the distal end of the deployment catheter or separate
manipulatable catheters may be articulated through various
controlling mechanisms such as push-pull wires manually or via
computer control
[0012] The deployment catheter may also be stabilized relative to
the tissue surface through various methods. For instance,
inflatable stabilizing balloons positioned along a length of the
catheter may be utilized, or tissue engagement anchors may be
passed through or along the deployment catheter for temporary
engagement of the underlying tissue.
[0013] In operation, after the imaging hood has been deployed,
fluid may be pumped at a positive pressure through the fluid
delivery lumen until the fluid fills the open area completely and
displaces any blood from within the open area. The fluid may
comprise any biocompatible fluid, e.g., saline, water, plasma,
Fluorinert.TM., etc., which is sufficiently transparent to allow
for relatively undistorted visualization through the fluid. The
fluid may be pumped continuously or intermittently to allow for
image capture by an optional processor which may be in
communication with the assembly.
[0014] The imaging hood may be formed into any number of
configurations and the imaging assembly may also be utilized with
any number of therapeutic tools which may be deployed through the
deployment catheter.
[0015] Variations of the inventive assemblies and their features
described herein may be used with other devices that provide
bounded regions. For example, U.S. Pat. No. 6,755,811 and US
Published Patent Application No. 2005/0059954, both to Constantz,
describe methods and devices for reducing mineral content of a
region of non-intimal vascular tissue. The entirety of each of
which is incorporated by reference herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1A shows a side view of one variation of a tissue
imaging apparatus during deployment from a sheath or delivery
catheter.
[0017] FIG. 1B shows the deployed tissue imaging apparatus of FIG.
1A having an optionally expandable hood or sheath attached to an
imaging and/or diagnostic catheter.
[0018] FIG. 1C shows an end view of a deployed imaging
apparatus.
[0019] FIGS. 1D to 1F show the apparatus of FIGS. 1A to 1C with an
additional lumen, e.g., for passage of a guidewire
therethrough.
[0020] FIGS. 1G-1J illustrate additional variations of the assembly
having visualization elements as well as illumination elements.
[0021] FIGS. 2A and 2B show one example of a deployed tissue imager
positioned against or adjacent to the tissue to be imaged and a
flow of fluid, such as saline, displacing blood from within the
expandable hood.
[0022] FIG. 3A shows an articulatable imaging assembly which may be
manipulated via push-pull wires or by computer control.
[0023] FIGS. 3B and 3C show steerable instruments, respectively,
where an articulatable delivery catheter may be steered within the
imaging hood or a distal portion of the deployment catheter itself
may be steered.
[0024] FIGS. 4A to 4C show side and cross-sectional end views,
respectively, of another variation having an off-axis imaging
capability.
[0025] FIGS. 4D-4G illustrates cross-sectional views of a variation
of a tissue imaging and manipulation assembly with off-axis
visualization capabilities.
[0026] FIG. 5 shows an illustrative view of an example of a tissue
imager advanced intravascularly within a heart for imaging tissue
regions within an atrial chamber.
[0027] FIGS. 6A to 6C illustrate deployment catheters having one or
more optional inflatable balloons or anchors for stabilizing the
device during a procedure.
[0028] FIGS. 7A and 7B illustrate a variation of an anchoring
mechanism such as a helical tissue piercing device for temporarily
stabilizing the imaging hood relative to a tissue surface.
[0029] FIG. 7C shows another variation for anchoring the imaging
hood having one or more tubular support members integrated with the
imaging hood; each support members may define a lumen therethrough
for advancing a helical tissue anchor within.
[0030] FIG. 8A shows an illustrative example of one variation of
how a tissue imager may be utilized with an imaging device.
[0031] FIG. 8B shows a further illustration of a hand-held
variation of the fluid delivery and tissue manipulation system.
[0032] FIGS. 9A to 9C illustrate an example of capturing several
images of the tissue at multiple regions.
[0033] FIGS. 10A and 10B show charts illustrating how fluid
pressure within the imaging hood may be coordinated with the
surrounding blood pressure; the fluid pressure in the imaging hood
may be coordinated with the blood pressure or it may be regulated
based upon pressure feedback from the blood.
[0034] FIG. 11A shows a side view of another variation of a tissue
imager having an imaging balloon within an expandable hood.
[0035] FIG. 11B shows another variation of a tissue imager
utilizing a translucent or transparent imaging balloon.
[0036] FIG. 12A shows another variation in which a flexible
expandable or distensible membrane may be incorporated within the
imaging hood to alter the volume of fluid dispensed.
[0037] FIGS. 12B and 12C show another variation in which the
imaging hood may be partially or selectively deployed from the
catheter to alter the area of the tissue being visualized as well
as the volume of the dispensed fluid.
[0038] FIGS. 12D-12F show variations of the imaging hood with an
inflatable members that displace fluids or other materials from the
hood.
[0039] FIGS. 13A and 13B show exemplary side and cross-sectional
views, respectively, of another variation in which the injected
fluid may be drawn back into the device for minimizing fluid input
into a body being treated.
[0040] FIGS. 14A to 14D show various configurations and methods for
configuring an imaging hood into a low-profile for delivery and/or
deployment.
[0041] FIGS. 15A and 15B show an imaging hood having an helically
expanding frame or support.
[0042] FIGS. 16A and 16B show another imaging hood having one or
more hood support members, which are pivotably attached at their
proximal ends to deployment catheter, integrated with a hood
membrane.
[0043] FIGS. 17A and 17B show yet another variation of the imaging
hood having at least two or more longitudinally positioned support
members supporting the imaging hood membrane where the support
members are movable relative to one another via a torquing or
pulling or pushing force.
[0044] FIGS. 18A and 18B show another variation where a distal
portion of the deployment catheter may have several pivoting
members which form a tubular shape in its low profile
configuration.
[0045] FIGS. 19A and 19B show another variation where the distal
portion of deployment catheter may be fabricated from a flexible
metallic or polymeric material to form a radially expanding
hood.
[0046] FIGS. 20A and 20B show another variation where the imaging
hood may be formed from a plurality of overlapping hood members
which overlie one another in an overlapping pattern.
[0047] FIG. 20C shows a variation of a hood having a conforming
section at the distal end.
[0048] FIGS. 21A and 21B show another example of an expandable hood
which is highly conformable against tissue anatomy with varying or
non-uniform surfaces.
[0049] FIG. 22A shows yet another example of an expandable hood
having a number of optional electrodes placed about the contact
edge or lip of the hood for sensing tissue contact or detecting
arrhythmias.
[0050] FIG. 22B shows another variation for conforming the imaging
hood against the underlying tissue where an inflatable contact edge
may be disposed around the circumference of the imaging hood.
[0051] FIG. 23 shows a variation of the system which may be
instrumented with a transducer for detecting the presence of blood
seeping back into the imaging hood.
[0052] FIGS. 24A and 24B show variations of the imaging hood
instrumented with sensors for detecting various physical
parameters; the sensors may be instrumented around the outer
surface of the imaging hood and also within the imaging hood.
[0053] FIGS. 25A and 25B show a variation where the imaging hood
may have one or more LEDs over the hood itself for providing
illumination of the tissue to be visualized.
[0054] FIGS. 26A and 26B show another variation in which a separate
illumination tool having one or more LEDs mounted thereon may be
utilized within the imaging hood.
[0055] FIG. 27 shows one example of how a therapeutic tool may be
advanced through the tissue imager for treating a tissue region of
interest.
[0056] FIG. 28 shows another example of a helical therapeutic tool
for treating the tissue region of interest.
[0057] FIG. 29 shows a variation of how a therapeutic tool may be
utilized with an expandable imaging balloon.
[0058] FIGS. 30A and 30B show alternative configurations for
therapeutic instruments which may be utilized; one variation is
shown having an angled instrument arm and another variation is
shown with an off-axis instrument arm.
[0059] FIGS. 31A to 31C show side and end views, respectively, of
an imaging system which may be utilized with an ablation probe.
[0060] FIGS. 32A and 32B show side and end views, respectively, of
another variation of the imaging hood with an ablation probe, where
the imaging hood may be enclosed for regulating a temperature of
the underlying tissue.
[0061] FIGS. 33A and 33B show an example in which the imaging fluid
itself may be altered in temperature to facilitate various
procedures upon the underlying tissue.
[0062] FIG. 33C illustrates a variation of a system using
ultrasound to treat the tissue under the hood.
[0063] FIGS. 34A and 34B show an example of a laser ring generator
which may be utilized with the imaging system and an example for
applying the laser ring generator within the left atrium of a heart
for treating atrial fibrillation.
[0064] FIG. 34C illustrates a variation of the system having a
visualization element located at the end of the catheter and/or on
the hood.
[0065] FIG. 34D illustrates another variation of a system according
to the present invention using an inflatable member for advancing
the device to a site.
[0066] FIGS. 35A to 35C show an example of an extendible cannula
generally comprising an elongate tubular member which may be
positioned within the deployment catheter during delivery and then
projected distally through the imaging hood and optionally
beyond.
[0067] FIGS. 36A and 36B show side and end views, respectively, of
an imaging hood having one or more tubular support members
integrated with the hood for passing instruments or tools
therethrough for treatment upon the underlying tissue.
[0068] FIGS. 37A and 37B illustrate how an imaging device may be
guided within a heart chamber to a region of interest utilizing a
lighted probe positioned temporarily within, e.g., a lumen of the
coronary sinus.
[0069] FIGS. 38A and 38B show an imaging hood having a removable
disk-shaped member for implantation upon the tissue surface.
[0070] FIGS. 39A to 39C show one method for implanting the
removable disk of FIGS. 38A and 38B.
[0071] FIGS. 40A and 40B illustrate an imaging hood having a
deployable anchor assembly attached to the tissue contact edge and
an assembly view of the anchors and the suture or wire connected to
the anchors, respectively
[0072] FIGS. 41A to 41D show one method for deploying the anchor
assembly of FIGS. 40A and 40B for closing an opening or wound.
[0073] FIGS. 41E-41F illustrates tissue imaging and manipulation
assemblies configured to deliver implants.
[0074] FIG. 42 shows another variation in which the imaging system
may be fluidly coupled to a dialysis unit for filtering a patient's
blood.
[0075] FIGS. 43A and 43B show a variation of the deployment
catheter having a first deployable hood and a second deployable
hood positioned distal to the first hood; the deployment catheter
may also have a side-viewing imaging element positioned between the
first and second hoods for imaging tissue between the expanded
hoods.
[0076] FIG. 43C illustrates another variation of a deployment
catheter 480 having a series of deployable hoods arranged to
produce a clear visual field.
[0077] FIGS. 44A and 44B show side and end views, respectively, of
a deployment catheter having a side-imaging balloon in an
un-inflated low-profile configuration.
[0078] FIGS. 45A to 45C show side, top, and end views,
respectively, of the inflated balloon of FIGS. 44A and 44B defining
a visualization field in the inflated balloon.
[0079] FIGS. 46A and 46B show side and cross-sectional end views,
respectively, for one method of use in visualizing a lesion upon a
vessel wall within the visualization field of the inflated balloon
from FIGS. 45A to 45C.
[0080] FIGS. 47A-47B illustrate a variation of a device according
to the present invention where components of the system allow for
blunt dissection of tissue.
[0081] FIG. 48A show a variation of a tissue imaging and
manipulation assembly including an elongate bypass portion.
[0082] FIGS. 48B-48C show the variation of FIG. 48A with a tissue
support flap.
[0083] FIG. 48D illustrates an off-center hood located about a
catheter.
[0084] FIG. 48E shows a variation of a tissue imaging and
manipulation assembly including an elongate portion that supplies
fluid to an area of tissue.
[0085] FIG. 48F shows a tissue imaging and manipulation assembly
including an occlusion member or balloon.
[0086] FIG. 49A-49E illustrate the use of an elongate member having
a plurality of openings to produce flow patterns within the
hood.
[0087] FIGS. 50A-50C illustrate variations of a tissue imaging and
manipulation assembly designed to translate or "walk" across tissue
surfaces when inserted within the body.
DETAILED DESCRIPTION OF THE INVENTION
[0088] A tissue-imaging and manipulation apparatus described below
is able to provide real-time images in vivo of tissue regions
within a body lumen such as a heart, which is filled with blood
flowing dynamically therethrough and is also able to provide
intravascular tools and instruments for performing various
procedures upon the imaged tissue regions. Such an apparatus may be
utilized for many procedures, e.g., facilitating trans-septal
access to the left atrium, cannulating the coronary sinus,
diagnosis of valve regurgitation/stenosis, valvuloplasty, atrial
appendage closure, arrhythmogenic focus ablation, among other
procedures.
[0089] One variation of a tissue access and imaging apparatus is
shown in the detail perspective views of FIGS. 1A to 1C. As shown
in FIG. 1A, tissue imaging and manipulation assembly 10 may be
delivered intravascularly through the patient's body in a
low-profile configuration via a delivery catheter or sheath 14. In
the case of treating tissue, such as the mitral valve located at
the outflow tract of the left atrium of the heart, it is generally
desirable to enter or access the left atrium while minimizing
trauma to the patient. To non-operatively effect such access, one
conventional approach involves puncturing the intra-atrial septum
from the right atrial chamber to the left atrial chamber in a
procedure commonly called a trans-septal procedure or septostomy.
For procedures such as percutaneous valve repair and replacement,
trans-septal access to the left atrial chamber of the heart may
allow for larger devices to be introduced into the venous system
than can generally be introduced percutaneously into the arterial
system.
[0090] When the imaging and manipulation assembly 10 is ready to be
utilized for imaging tissue, imaging hood 12 may be advanced
relative to catheter 14 and deployed from a distal opening of
catheter 14, as shown by the arrow. Upon deployment, imaging hood
12 may be unconstrained to expand or open into a deployed imaging
configuration, as shown in FIG. 1B. Imaging hood 12 may be
fabricated from a variety of pliable or conformable biocompatible
material including but not limited to, e.g., polymeric, plastic, or
woven materials. One example of a woven material is Kevlar.RTM. (E.
I. du Pont de Nemours, Wilmington, Del.), which is an aramid and
which can be made into thin, e.g., less than 0.001 in., materials
which maintain enough integrity for such applications described
herein. Moreover, the imaging hood 12 may be fabricated from a
translucent or opaque material and in a variety of different colors
to optimize or attenuate any reflected lighting from surrounding
fluids or structures, i.e., anatomical or mechanical structures or
instruments. In either case, imaging hood 12 may be fabricated into
a uniform structure or a scaffold-supported structure, in which
case a scaffold made of a shape memory alloy, such as Nitinol, or a
spring steel, or plastic, etc., may be fabricated and covered with
the polymeric, plastic, or woven material.
[0091] Imaging hood 12 may be attached at interface 24 to a
deployment catheter 16 which may be translated independently of
deployment catheter or sheath 14. Attachment of interface 24 may be
accomplished through any number of conventional methods. Deployment
catheter 16 may define a fluid delivery lumen 18 as well as an
imaging lumen 20 within which an optical imaging fiber or assembly
may be disposed for imaging tissue. When deployed, imaging hood 12
may expand into any number of shapes, e.g., cylindrical, conical as
shown, semi-spherical, etc., provided that an open area or field 26
is defined by imaging hood 12. The open area 26 is the area within
which the tissue region of interest may be imaged. Imaging hood 12
may also define an atraumatic contact lip or edge 22 for placement
or abutment against the tissue region of interest. Moreover, the
diameter of imaging hood 12 at its maximum fully deployed diameter,
e.g., at contact lip or edge 22, is typically greater relative to a
diameter of the deployment catheter 16 (although a diameter of
contact lip or edge 22 may be made to have a smaller or equal
diameter of deployment catheter 16). For instance, the contact edge
diameter may range anywhere from 1 to 5 times (or even greater, as
practicable) a diameter of deployment catheter 16. FIG. 1C shows an
end view of the imaging hood 12 in its deployed configuration. Also
shown are the contact lip or edge 22 and fluid delivery lumen 18
and imaging lumen 20.
[0092] The imaging and manipulation assembly 10 may additionally
define a guidewire lumen therethrough, e.g., a concentric or
eccentric lumen, as shown in the side and end views, respectively,
of FIGS. 1D to 1F. The deployment catheter 16 may define guidewire
lumen 19 for facilitating the passage of the system over or along a
guidewire 17, which may be advanced intravascularly within a body
lumen. The deployment catheter 16 may then be advanced over the
guidewire 17, as generally known in the art.
[0093] In operation, after imaging hood 12 has been deployed, as in
FIG. 1B, and desirably positioned against the tissue region to be
imaged along contact edge 22, the displacing fluid may be pumped at
positive pressure through fluid delivery lumen 18 until the fluid
fills open area 26 completely and displaces any fluid 28 from
within open area 26. The displacing fluid flow may be laminarized
to improve its clearing effect and to help prevent blood from
re-entering the imaging hood 12. Alternatively, fluid flow may be
started before the deployment takes place. The displacing fluid,
also described herein as imaging fluid, may comprise any
biocompatible fluid, e.g., saline, water, plasma, etc., which is
sufficiently transparent to allow for relatively undistorted
visualization through the fluid. Alternatively or additionally, any
number of therapeutic drugs may be suspended within the fluid or
may comprise the fluid itself which is pumped into open area 26 and
which is subsequently passed into and through the heart and the
patient body.
[0094] FIG. 1G illustrates another variation of a tissue imaging
and manipulation assembly 10. In this variation, the assembly 10
comprises one or more visualization element 52 located in an
"off-axis" position within the hood 12. The benefits of the
"off-axis" configuration are discussed below. However, the
assemblies of the present invention may comprise anywhere from a
single visualization element 52 to several elements 52. For
example, some variations of the assembly 10 may include at least
two visualization elements 52 to enable 3-dimensional imaging of
the open area within the hood 12. For example, the elements 52 may
be sufficiently spaced around the perimeter of the hood 12 to allow
generation of a 3-dimensional image. It is contemplated that
optical fibers may be used in place of or in addition to the
visualization elements shown in FIG. 1G. Additional means of
obtaining a 3D image includes separating a single imaging element
into two or more segments that can look at a target zone from two
different angles. For example, such a stereoscopic visualization
element may include a lenticular lens layer and light sensor array,
the lenticular lens layer includes a plurality of lenticular
elements, the sight sensor array includes a plurality of light
sensors, where selected light sensors detect light at a
predetermined range of wavelengths and where other light sensors
detect light at another predetermined range of wavelengths, and
where each of the lenticular elements is located in front of a
selected group of the light sensors, to direct light from different
directions to different light sensors within the selected group of
the light sensors. Next, the views are processed producing a 3D
image. Examples of such 3D imaging equipment is found in U.S. Pat.
Nos. 6,396,873 and 6,704,043 both to Goldstein et al. and entitled
"Optical Device". The entirety of both of which are incorporated by
reference. Such products may be supplied by Visionsense, Inc. of
Petah Tivak, Israel. An additional way to create a 3D image is by
using two image guides made from optical fibers and spacing them
apart by a small distance (0.1-10 mm) and combining these two
images in one cohesive 3D image.
[0095] FIG. 1H illustrates a cross-sectional view taken along the
line 1H-1H of FIG. 1G. As illustrated, a variation of the catheter
16 may include co-extruded channels 32 to carry wires or optical
fibers running along the length or a portion of a length of the
catheter 16. The channels 32 may permit connection of a
visualization element to imaging equipment without taking up space
from the remaining lumens 32. These channels can also contain
electrical wires that carry the signal from an imaging detector to
a sensor/processor outside the patient.
[0096] Alternatively, the channels 32 may provide a light source or
supply. FIG. 11 illustrates anther variation of a distal end of a
catheter according to the present invention. In this variation, the
catheter will include a variety of lumens 32. As noted herein, the
lumens 32 may be used for visualization, working channels,
aspiration, delivery of tools, etc. The variation of FIG. 11 also
illustrates the catheter 16 as having a number of illumination
sources 36. The illumination sources may small illumination optical
fibers or any other illumination source as commonly used. In
another variation of the invention, the lumens 38 may provide
irrigation or other fluids.
[0097] FIG. 1J illustrates another variation of a tissue imaging
and manipulation assembly 10. In this variation, the hood 12
includes both a visualization component 52 and an illumination
source 36 positioned on the interior surface of the hood 12. Again,
as noted above, although the figure illustrates the hood 12 as
containing a single visualization element 52 and a single
illumination source 36 (such as a fiber, a LED, other light
emitting source) variations of the device may include additional
elements 52 or illumination sources.
[0098] As seen in the example of FIGS. 2A and 2B, deployment
catheter 16 may be manipulated to position deployed imaging hood 12
against or near the underlying tissue region of interest to be
imaged, in this example a portion of annulus A of mitral valve MV
within the left atrial chamber. As the surrounding blood 30 flows
around imaging hood 12 and within open area 26 defined within
imaging hood 12, as seen in FIG. 2A, the underlying annulus A is
obstructed by the opaque blood 30 and is difficult to view through
the imaging lumen 20. The translucent fluid 28, such as saline, may
then be pumped through fluid delivery lumen 18, intermittently or
continuously, until the blood 30 is at least partially, and
preferably completely, displaced from within open area 26 by fluid
28, as shown in FIG. 2B.
[0099] Although contact edge 22 need not directly contact the
underlying tissue, it is at least preferably brought into close
proximity to the tissue such that the flow of clear fluid 28 from
open area 26 may be maintained to inhibit significant backflow of
blood 30 back into open area 26. Contact edge 22 may also be made
of a soft elastomeric material such as certain soft grades of
silicone or polyurethane, as typically known, to help contact edge
22 conform to an uneven or rough underlying anatomical tissue
surface. Once the blood 30 has been displaced from imaging hood 12,
an image may then be viewed of the underlying tissue through the
clear fluid 30. This image may then be recorded or available for
real-time viewing for performing a therapeutic procedure. The
positive flow of fluid 28 may be maintained continuously to provide
for clear viewing of the underlying tissue. Alternatively, the
fluid 28 may be pumped temporarily or sporadically only until a
clear view of the tissue is available to be imaged and recorded, at
which point the fluid flow 28 may cease and blood 30 may be allowed
to seep or flow back into imaging hood 12. This process may be
repeated a number of times at the same tissue region or at multiple
tissue regions.
[0100] In desirably positioning the assembly at various regions
within the patient body, a number of articulation and manipulation
controls may be utilized. For example, as shown in the
articulatable imaging assembly 40 in FIG. 3A, one or more push-pull
wires 42 may be routed through deployment catheter 16 for steering
the distal end portion of the device in various directions 46 to
desirably position the imaging hood 12 adjacent to a region of
tissue to be visualized. Depending upon the positioning and the
number of push-pull wires 42 utilized, deployment catheter 16 and
imaging hood 12 may be articulated into any number of
configurations 44. The push-pull wire or wires 42 may be
articulated via their proximal ends from outside the patient body
manually utilizing one or more controls. Alternatively, deployment
catheter 16 may be articulated by computer control, as further
described below.
[0101] Additionally or alternatively, an articulatable delivery
catheter 48, which may be articulated via one or more push-pull
wires and having an imaging lumen and one or more working lumens,
may be delivered through the deployment catheter 16 and into
imaging hood 12. With a distal portion of articulatable delivery
catheter 48 within imaging hood 12, the clear displacing fluid may
be pumped through delivery catheter 48 or deployment catheter 16 to
clear the field within imaging hood 12. As shown in FIG. 3B, the
articulatable delivery catheter 48 may be articulated within the
imaging hood to obtain a better image of tissue adjacent to the
imaging hood 12. Moreover, articulatable delivery catheter 48 may
be articulated to direct an instrument or tool passed through the
catheter 48, as described in detail below, to specific areas of
tissue imaged through imaging hood 12 without having to reposition
deployment catheter 16 and re-clear the imaging field within hood
12.
[0102] Alternatively, rather than passing an articulatable delivery
catheter 48 through the deployment catheter 16, a distal portion of
the deployment catheter 16 itself may comprise a distal end 49
which is articulatable within imaging hood 12, as shown in FIG. 3C.
Directed imaging, instrument delivery, etc., may be accomplished
directly through one or more lumens within deployment catheter 16
to specific regions of the underlying tissue imaged within imaging
hood 12.
[0103] Visualization within the imaging hood 12 may be accomplished
through an imaging lumen 20 defined through deployment catheter 16,
as described above. In such a configuration, visualization is
available in a straight-line manner, i.e., images are generated
from the field distally along a longitudinal axis defined by the
deployment catheter 16. Alternatively or additionally, an
articulatable imaging assembly having a pivotable support member 50
may be connected to, mounted to, or otherwise passed through
deployment catheter 16 to provide for visualization off-axis
relative to the longitudinal axis defined by deployment catheter
16, as shown in FIG. 4A. Support member 50 may have an imaging
element 52, e.g., a CCD or CMOS imager or optical fiber, attached
at its distal end with its proximal end connected to deployment
catheter 16 via a pivoting connection 54.
[0104] If one or more optical fibers are utilized for imaging, the
optical fibers 58 may be passed through deployment catheter 16, as
shown in the cross-section of FIG. 4B, and routed through the
support member 50. The use of optical fibers 58 may provide for
increased diameter sizes of the one or several lumens 56 through
deployment catheter 16 for the passage of diagnostic and/or
therapeutic tools therethrough. Alternatively, electronic chips,
such as a charge coupled device (CCD) or a CMOS imager, which are
typically known, may be utilized in place of the optical fibers 58,
in which case the electronic imager may be positioned in the distal
portion of the deployment catheter 16 with electric wires being
routed proximally through the deployment catheter 16.
Alternatively, the electronic imagers may be wirelessly coupled to
a receiver for the wireless transmission of images. Additional
optical fibers or light emitting diodes (LEDs) can be used to
provide lighting for the image or operative theater, as described
below in further detail. Support member 50 may be pivoted via
connection 54 such that the member 50 can be positioned in a
low-profile configuration within channel or groove 60 defined in a
distal portion of catheter 16, as shown in the cross-section of
FIG. 4C. During intravascular delivery of deployment catheter 16
through the patient body, support member 50 can be positioned
within channel or groove 60 with imaging hood 12 also in its
low-profile configuration. During visualization, imaging hood 12
may be expanded into its deployed configuration and support member
50 may be deployed into its off-axis configuration for imaging the
tissue adjacent to hood 12, as in FIG. 4A. Other configurations for
support member 50 for off-axis visualization may be utilized, as
desired.
[0105] FIG. 4D illustrates another variation of a tissue imaging
and manipulation assembly 10 with off-axis visualization
capabilities. As shown in FIG. 4D, when the hood 12 is in a
collapsed position (typically when navigated to a site.) In this
variation, the visualization element 52 is adapted such that it may
align with an axis of the assembly 10 especially during placement
of the assembly 10 at a desired site.
[0106] FIG. 4E illustrates the assembly 10 of FIG. 4D when the
device reaches the target site. As shown, the hood 12 expands to
define the open area. Next, the visualization element 52 may
articulate out of alignment with the catheter 16. This
configuration permits the device to have a low profile delivery
state during delivery and subsequently expand to define the open
area. The ability of the visualization element 52 to reposition
"off-axis" allows the assembly 10 to accommodate large working
instruments through the catheter 16 and substantially reduce the
space requirements to accommodate the visualization element. The
invention also contemplates placing optical fibers in a similar
manner so that the fibers may reposition "off-axis" in a similar
manner to the visualization element 52 as depicted. The off-axis
visualization allows a more natural operating view akin to how a
primate's eyes and hands are positioned relative to one
another.
[0107] FIG. 4F and FIG. 4G illustrates the assembly 10 where the
visualization element 52 is slidable in and out of the hood 12. For
instance, when deployed, as shown in FIG. 4F, the visualization
element 52 is located along the interior of the hood 12. When in a
collapsed position, as shown in FIG. 4G, the visualization element
52 extends out of the hood 12. This variation is useful to allow
the hood 12 to compress or collapse to a smaller size without
having to accommodate the visualization element 52. Also, the
visualization element 52 may be used when navigating the device 10
to a desired site.
[0108] FIG. 5 shows an illustrative cross-sectional view of a heart
H having tissue regions of interest being viewed via an imaging
assembly 10. In this example, delivery catheter assembly 70 may be
introduced percutaneously into the patient's vasculature and
advanced through the superior vena cava SVC and into the right
atrium RA. The delivery catheter or sheath 72 may be articulated
through the atrial septum AS and into the left atrium LA for
viewing or treating the tissue, e.g., the annulus A, surrounding
the mitral valve MV. As shown, deployment catheter 16 and imaging
hood 12 may be advanced out of delivery catheter 72 and brought
into contact or in proximity to the tissue region of interest. In
other examples, delivery catheter assembly 70 may be advanced
through the inferior vena cava IVC, if so desired. Moreover, other
regions of the heart H, e.g., the right ventricle RV or left
ventricle LV, may also be accessed and imaged or treated by imaging
assembly 10.
[0109] In accessing regions of the heart H or other parts of the
body, the delivery catheter or sheath 14 may comprise a
conventional intra-vascular catheter or an endoluminal delivery
device. Alternatively, robotically-controlled delivery catheters
may also be optionally utilized with the imaging assembly described
herein, in which case a computer-controller 74 may be used to
control the articulation and positioning of the delivery catheter
14. An example of a robotically-controlled delivery catheter which
may be utilized is described in further detail in US Pat. Pub.
2002/0087169 A1 to Brock et al. entitled "Flexible Instrument",
which is incorporated herein by reference in its entirety. Other
robotically-controlled delivery catheters manufactured by Hansen
Medical, Inc. (Mountain View, Calif.) may also be utilized with the
delivery catheter 14.
[0110] To facilitate stabilization of the deployment catheter 16
during a procedure, one or more inflatable balloons or anchors 76
may be positioned along the length of catheter 16, as shown in FIG.
6A. For example, when utilizing a trans-septal approach across the
atrial septum AS into the left atrium LA, the inflatable balloons
76 may be inflated from a low-profile into their expanded
configuration to temporarily anchor or stabilize the catheter 16
position relative to the heart H. FIG. 6B shows a first balloon 78
inflated while FIG. 6C also shows a second balloon 80 inflated
proximal to the first balloon 78. In such a configuration, the
septal wall AS may be wedged or sandwiched between the balloons 78,
80 to temporarily stabilize the catheter 16 and imaging hood 12. A
single balloon 78 or both balloons 78, 80 may be used. Other
alternatives may utilize expandable mesh members, malecots, or any
other temporary expandable structure. After a procedure has been
accomplished, the balloon assembly 76 may be deflated or
re-configured into a low-profile for removal of the deployment
catheter 16.
[0111] To further stabilize a position of the imaging hood 12
relative to a tissue surface to be imaged, various anchoring
mechanisms may be optionally employed for temporarily holding the
imaging hood 12 against the tissue. Such anchoring mechanisms may
be particularly useful for imaging tissue which is subject to
movement, e.g., when imaging tissue within the chambers of a
beating heart. A tool delivery catheter 82 having at least one
instrument lumen and an optional visualization lumen may be
delivered through deployment catheter 16 and into an expanded
imaging hood 12. As the imaging hood 12 is brought into contact
against a tissue surface T to be examined, an anchoring mechanisms
such as a helical tissue piercing device 84 may be passed through
the tool delivery catheter 82, as shown in FIG. 7A, and into
imaging hood 12.
[0112] The helical tissue engaging device 84 may be torqued from
its proximal end outside the patient body to temporarily anchor
itself into the underlying tissue surface T. Once embedded within
the tissue T, the helical tissue engaging device 84 may be pulled
proximally relative to deployment catheter 16 while the deployment
catheter 16 and imaging hood 12 are pushed distally, as indicated
by the arrows in FIG. 7B, to gently force the contact edge or lip
22 of imaging hood against the tissue T. The positioning of the
tissue engaging device 84 may be locked temporarily relative to the
deployment catheter 16 to ensure secure positioning of the imaging
hood 12 during a diagnostic or therapeutic procedure within the
imaging hood 12. After a procedure, tissue engaging device 84 may
be disengaged from the tissue by torquing its proximal end in the
opposite direction to remove the anchor form the tissue T and the
deployment catheter 16 may be repositioned to another region of
tissue where the anchoring process may be repeated or removed from
the patient body. The tissue engaging device 84 may also be
constructed from other known tissue engaging devices such as
vacuum-assisted engagement or grasper-assisted engagement tools,
among others.
[0113] Although a helical anchor 84 is shown, this is intended to
be illustrative and other types of temporary anchors may be
utilized, e.g., hooked or barbed anchors, graspers, etc. Moreover,
the tool delivery catheter 82 may be omitted entirely and the
anchoring device may be delivered directly through a lumen defined
through the deployment catheter 16.
[0114] In another variation where the tool delivery catheter 82 may
be omitted entirely to temporarily anchor imaging hood 12, FIG. 7C
shows an imaging hood 12 having one or more tubular support members
86, e.g., four support members 86 as shown, integrated with the
imaging hood 12. The tubular support members 86 may define lumens
therethrough each having helical tissue engaging devices 88
positioned within. When an expanded imaging hood 12 is to be
temporarily anchored to the tissue, the helical tissue engaging
devices 88 may be urged distally to extend from imaging hood 12 and
each may be torqued from its proximal end to engage the underlying
tissue T. Each of the helical tissue engaging devices 88 may be
advanced through the length of deployment catheter 16 or they may
be positioned within tubular support members 86 during the delivery
and deployment of imaging hood 12. Once the procedure within
imaging hood 12 is finished, each of the tissue engaging devices 88
may be disengaged from the tissue and the imaging hood 12 may be
repositioned to another region of tissue or removed from the
patient body.
[0115] An illustrative example is shown in FIG. 8A of a tissue
imaging assembly connected to a fluid delivery system 90 and to an
optional processor 98 and image recorder and/or viewer 100. The
fluid delivery system 90 may generally comprise a pump 92 and an
optional valve 94 for controlling the flow rate of the fluid into
the system. A fluid reservoir 96, fluidly connected to pump 92, may
hold the fluid to be pumped through imaging hood 12. An optional
central processing unit or processor 98 may be in electrical
communication with fluid delivery system 90 for controlling flow
parameters such as the flow rate and/or velocity of the pumped
fluid. The processor 98 may also be in electrical communication
with an image recorder and/or viewer 100 for directly viewing the
images of tissue received from within imaging hood 12. Imager
recorder and/or viewer 100 may also be used not only to record the
image but also the location of the viewed tissue region, if so
desired.
[0116] Optionally, processor 98 may also be utilized to coordinate
the fluid flow and the image capture. For instance, processor 98
may be programmed to provide for fluid flow from reservoir 96 until
the tissue area has been displaced of blood to obtain a clear
image. Once the image has been determined to be sufficiently clear,
either visually by a practitioner or by computer, an image of the
tissue may be captured automatically by recorder 100 and pump 92
may be automatically stopped or slowed by processor 98 to cease the
fluid flow into the patient. Other variations for fluid delivery
and image capture are, of course, possible and the aforementioned
configuration is intended only to be illustrative and not
limiting.
[0117] FIG. 8B shows a further illustration of a hand-held
variation of the fluid delivery and tissue manipulation system 110.
In this variation, system 110 may have a housing or handle assembly
112 which can be held or manipulated by the physician from outside
the patient body. The fluid reservoir 114, shown in this variation
as a syringe, can be fluidly coupled to the handle assembly 112 and
actuated via a pumping mechanism 116, e.g., lead screw. Fluid
reservoir 114 may be a simple reservoir separated from the handle
assembly 112 and fluidly coupled to handle assembly 112 via one or
more tubes. The fluid flow rate and other mechanisms may be metered
by the electronic controller 118.
[0118] Deployment of imaging hood 12 may be actuated by a hood
deployment switch 120 located on the handle assembly 112 while
dispensation of the fluid from reservoir 114 may be actuated by a
fluid deployment switch 122, which can be electrically coupled to
the controller 118. Controller 118 may also be electrically coupled
to a wired or wireless antenna 124 optionally integrated with the
handle assembly 112, as shown in the figure. The wireless antenna
124 can be used to wirelessly transmit images captured from the
imaging hood 12 to a receiver, e.g., via Bluetooth.RTM. wireless
technology (Bluetooth SIG, Inc., Bellevue, Wash.), RF, etc., for
viewing on a monitor 128 or for recording for later viewing.
[0119] Articulation control of the deployment catheter 16, or a
delivery catheter or sheath 14 through which the deployment
catheter 16 may be delivered, may be accomplished by computer
control, as described above, in which case an additional controller
may be utilized with handle assembly 112. In the case of manual
articulation, handle assembly 112 may incorporate one or more
articulation controls 126 for manual manipulation of the position
of deployment catheter 16. Handle assembly 112 may also define one
or more instrument ports 130 through which a number of
intravascular tools may be passed for tissue manipulation and
treatment within imaging hood 12, as described further below.
Furthermore, in certain procedures, fluid or debris may be sucked
into imaging hood 12 for evacuation from the patient body by
optionally fluidly coupling a suction pump 132 to handle assembly
112 or directly to deployment catheter 16.
[0120] As described above, fluid may be pumped continuously into
imaging hood 12 to provide for clear viewing of the underlying
tissue. Alternatively, fluid may be pumped temporarily or
sporadically only until a clear view of the tissue is available to
be imaged and recorded, at which point the fluid flow may cease and
the blood may be allowed to seep or flow back into imaging hood 12.
FIGS. 9A to 9C illustrate an example of capturing several images of
the tissue at multiple regions. Deployment catheter 16 may be
desirably positioned and imaging hood 12 deployed and brought into
position against a region of tissue to be imaged, in this example
the tissue surrounding a mitral valve MV within the left atrium of
a patient's heart. The imaging hood 12 may be optionally anchored
to the tissue, as described above, and then cleared by pumping the
imaging fluid into the hood 12. Once sufficiently clear, the tissue
may be visualized and the image captured by control electronics
118. The first captured image 140 may be stored and/or transmitted
wirelessly 124 to a monitor 128 for viewing by the physician, as
shown in FIG. 9A.
[0121] The deployment catheter 16 may be then repositioned to an
adjacent portion of mitral valve MV, as shown in FIG. 9B, where the
process may be repeated to capture a second image 142 for viewing
and/or recording. The deployment catheter 16 may again be
repositioned to another region of tissue, as shown in FIG. 9C,
where a third image 144 may be captured for viewing and/or
recording. This procedure may be repeated as many times as
necessary for capturing a comprehensive image of the tissue
surrounding mitral valve MV, or any other tissue region. When the
deployment catheter 16 and imaging hood 12 is repositioned from
tissue region to tissue region, the pump may be stopped during
positioning and blood or surrounding fluid may be allowed to enter
within imaging hood 12 until the tissue is to be imaged, where the
imaging hood 12 may be cleared, as above.
[0122] As mentioned above, when the imaging hood 12 is cleared by
pumping the imaging fluid within for clearing the blood or other
bodily fluid, the fluid may be pumped continuously to maintain the
imaging fluid within the hood 12 at a positive pressure or it may
be pumped under computer control for slowing or stopping the fluid
flow into the hood 12 upon detection of various parameters or until
a clear image of the underlying tissue is obtained. The control
electronics 118 may also be programmed to coordinate the fluid flow
into the imaging hood 12 with various physical parameters to
maintain a clear image within imaging hood 12.
[0123] One example is shown in FIG. 10A which shows a chart 150
illustrating how fluid pressure within the imaging hood 12 may be
coordinated with the surrounding blood pressure. Chart 150 shows
the cyclical blood pressure 156 alternating between diastolic
pressure 152 and systolic pressure 154 over time T due to the
beating motion of the patient heart. The fluid pressure of the
imaging fluid, indicated by plot 160, within imaging hood 12 may be
automatically timed to correspond to the blood pressure changes 160
such that an increased pressure is maintained within imaging hood
12 which is consistently above the blood pressure 156 by a slight
increase .DELTA.P, as illustrated by the pressure difference at the
peak systolic pressure 158. This pressure difference, .DELTA.P, may
be maintained within imaging hood 12 over the pressure variance of
the surrounding blood pressure to maintain a positive imaging fluid
pressure within imaging hood 12 to maintain a clear view of the
underlying tissue. One benefit of maintaining a constant .DELTA.P
is a constant flow and maintenance of a clear field.
[0124] FIG. 10B shows a chart 162 illustrating another variation
for maintaining a clear view of the underlying tissue where one or
more sensors within the imaging hood 12, as described in further
detail below, maybe configured to sense pressure changes within the
imaging hood 12 and to correspondingly increase the imaging fluid
pressure within imaging hood 12. This may result in a time delay,
.DELTA.T, as illustrated by the shifted fluid pressure 160 relative
to the cycling blood pressure 156, although the time delay .DELTA.T
may be negligible in maintaining the clear image of the underlying
tissue. Predictive software algorithms can also be used to
substantially eliminate this time delay by predicting when the next
pressure wave peak will arrive and by increasing the pressure ahead
of the pressure wave's arrival by an amount of time substantially
equal to the aforementioned time delay to essentially cancel the
time delay out.
[0125] The variations in fluid pressure within imaging hood 12 may
be accomplished in part due to the nature of imaging hood 12. An
inflatable balloon, which is conventionally utilized for imaging
tissue, may be affected by the surrounding blood pressure changes.
On the other hand, an imaging hood 12 retains a constant volume
therewithin and is structurally unaffected by the surrounding blood
pressure changes, thus allowing for pressure increases therewithin.
The material that hood 12 is made from may also contribute to the
manner in which the pressure is modulated within this hood 12. A
stiffer hood material, such as high durometer polyurethane or
Nylon, may facilitate the maintaining of an open hood when
deployed. On the other hand, a relatively lower durometer or softer
material, such as a low durometer PVC or polyurethane, may collapse
from the surrounding fluid pressure and may not adequately maintain
a deployed or expanded hood.
[0126] Turning now to the imaging hood, other variations of the
tissue imaging assembly may be utilized, as shown in FIG. 11A,
which shows another variation comprising an additional imaging
balloon 172 within an imaging hood 174. In this variation, an
expandable balloon 172 having a translucent skin may be positioned
within imaging hood 174. Balloon 172 may be made from any
distensible biocompatible material having sufficient translucent
properties which allow for visualization therethrough. Once the
imaging hood 174 has been deployed against the tissue region of
interest, balloon 172 may be filled with a fluid, such as saline,
or less preferably a gas, until balloon 172 has been expanded until
the blood has been sufficiently displaced. The balloon 172 may thus
be expanded proximal to or into contact against the tissue region
to be viewed. The balloon 172 can also be filled with contrast
media to allow it to be viewed on fluoroscopy to aid in its
positioning. The imager, e.g., fiber optic, positioned within
deployment catheter 170 may then be utilized to view the tissue
region through the balloon 172 and any additional fluid which may
be pumped into imaging hood 174 via one or more optional fluid
ports 176, which may be positioned proximally of balloon 172 along
a portion of deployment catheter 170. Alternatively, balloon 172
may define one or more holes over its surface which allow for
seepage or passage of the fluid contained therein to escape and
displace the blood from within imaging hood 174.
[0127] FIG. 11B shows another alternative in which balloon 180 may
be utilized alone. Balloon 180, attached to deployment catheter
178, may be filled with fluid, such as saline or contrast media,
and is preferably allowed to come into direct contact with the
tissue region to be imaged.
[0128] FIG. 12A shows another alternative in which deployment
catheter 16 incorporates imaging hood 12, as above, and includes an
additional flexible membrane 182 within imaging hood 12. Flexible
membrane 182 may be attached at a distal end of catheter 16 and
optionally at contact edge 22. Imaging hood 12 may be utilized, as
above, and membrane 182 may be deployed from catheter 16 in vivo or
prior to placing catheter 16 within a patient to reduce the volume
within imaging hood 12. The volume may be reduced or minimized to
reduce the amount of fluid dispensed for visualization or may be
reduced depending upon the area of tissue to be visualized.
[0129] FIGS. 12B and 12C show yet another alternative in which
imaging hood 186 may be withdrawn proximally within deployment
catheter 184 or deployed distally from catheter 186, as shown, to
vary the volume of imaging hood 186 and thus the volume of
dispensed fluid. Imaging hood 186 may be seen in FIG. 12B as being
partially deployed from, e.g., a circumferentially defined lumen
within catheter 184, such as annular lumen 188. The underlying
tissue may be visualized with imaging hood 186 only partially
deployed. Alternatively, imaging hood 186' may be fully deployed,
as shown in FIG. 12C, by urging hood 186' distally out from annular
lumen 188. In this expanded configuration, the area of tissue to be
visualized may be increased as hood 186' is expanded
circumferentially.
[0130] FIG. 12D illustrates another variation of a tissue imaging
and manipulation assembly 10. In this variation, the hood 12
includes an inflatable member 520 (e.g., a balloon, bladder, or
fillable membrane) that is coupled to a fluid source 522. The
inflatable member 520 may be constructed from a clear material.
Upon expansion of the hood 12, the inflatable member 520 fills with
a clear fluid as shown in FIG. 12E. As the inflatable member 520
expands, it displaces fluids and other substances from within the
hood 12 (as shown by the arrows). Because the member 520 and fluid
are clear, the visualization element 52 is still able to visualize
the tissue in the open area of the hood 12. FIG. 12E illustrates
yet another principle of an assembly 10 as described herein. In
this variation, the hood 12 includes two or more inflatable members
520, 524. The inflatable members 520, 524 function to displace
fluids from the hood 12 while permitting visualization. However,
use of two or more inflatable members 520, 524 permits advancement
of a tool or device 526 between the inflatable members. In another
variation, the inflatable member(s) is constructed from a material
having an index of refraction close to or matching that of the
displacement liquid. This selection of the index of essentially
allows the membrane to "disappear" and not interfere with
visualization.
[0131] FIGS. 13A and 13B show perspective and cross-sectional side
views, respectively, of yet another variation of imaging assembly
which may utilize a fluid suction system for minimizing the amount
of fluid injected into the patient's heart or other body lumen
during tissue visualization. Deployment catheter 190 in this
variation may define an inner tubular member 196 which may be
integrated with deployment catheter 190 or independently
translatable. Fluid delivery lumen 198 defined through member 196
may be fluidly connected to imaging hood 192, which may also define
one or more open channels 194 over its contact lip region. Fluid
pumped through fluid delivery lumen 198 may thus fill open area 202
to displace any blood or other fluids or objects therewithin. As
the clear fluid is forced out of open area 202, it may be sucked or
drawn immediately through one or more channels 194 and back into
deployment catheter 190. Tubular member 196 may also define one or
more additional working channels 200 for the passage of any tools
or visualization devices.
[0132] In deploying the imaging hood in the examples described
herein, the imaging hood may take on any number of configurations
when positioned or configured for a low-profile delivery within the
delivery catheter, as shown in the examples of FIGS. 14A to 14D.
These examples are intended to be illustrative and are not intended
to be limiting in scope. FIG. 14A shows one example in which
imaging hood 212 may be compressed within catheter 210 by folding
hood 212 along a plurality of pleats. Hood 212 may also comprise
scaffolding or frame 214 made of a super-elastic or shape memory
material or alloy, e.g., Nitinol, Elgiloy, shape memory polymers,
electroactive polymers, or a spring stainless steel. The shape
memory material may act to expand or deploy imaging hood 212 into
its expanded configuration when urged in the direction of the arrow
from the constraints of catheter 210.
[0133] FIG. 14B shows another example in which imaging hood 216 may
be expanded or deployed from catheter 210 from a folded and
overlapping configuration. Frame or scaffolding 214 may also be
utilized in this example. FIG. 14C shows yet another example in
which imaging hood 218 may be rolled, inverted, or everted upon
itself for deployment. In yet another example, FIG. 14D shows a
configuration in which imaging hood 220 may be fabricated from an
extremely compliant material which allows for hood 220 to be simply
compressed into a low-profile shape. From this low-profile
compressed shape, simply releasing hood 220 may allow for it to
expand into its deployed configuration, especially if a scaffold or
frame of a shape memory or superelastic material, e.g., Nitinol, is
utilized in its construction.
[0134] Another variation for expanding the imaging hood is shown in
FIGS. 15A and 15B which illustrates a helically expanding frame or
support 230. In its constrained low-profile configuration, shown in
FIG. 15A, helical frame 230 may be integrated with the imaging hood
12 membrane. When free to expand, as shown in FIG. 15B, helical
frame 230 may expand into a conical or tapered shape. Helical frame
230 may alternatively be made out of heat-activated Nitinol to
allow it to expand upon application of a current.
[0135] FIGS. 16A and 16B show yet another variation in which
imaging hood 12 may comprise one or more hood support members 232
integrated with the hood membrane. These longitudinally attached
support members 232 may be pivotably attached at their proximal
ends to deployment catheter 16. One or more pullwires 234 may be
routed through the length of deployment catheter 16 and extend
through one or more openings 238 defined in deployment catheter 16
proximally to imaging hood 12 into attachment with a corresponding
support member 232 at a pullwire attachment point 236. The support
members 232 may be fabricated from a plastic or metal, such as
stainless steel. Alternatively, the support members 232 may be made
from a superelastic or shape memory alloy, such as Nitinol, which
may self-expand into its deployed configuration without the use or
need of pullwires. A heat-activated Nitinol may also be used which
expands upon the application of thermal energy or electrical
energy. In another alternative, support members 232 may also be
constructed as inflatable lumens utilizing, e.g., PET balloons.
From its low-profile delivery configuration shown in FIG. 16A, the
one or more pullwires 234 may be tensioned from their proximal ends
outside the patient body to pull a corresponding support member 232
into a deployed configuration, as shown in FIG. 16B, to expand
imaging hood 12. To reconfigure imaging hood 12 back into its low
profile, deployment catheter 16 may be pulled proximally into a
constraining catheter or the pullwires 234 may be simply pushed
distally to collapse imaging hood 12.
[0136] FIGS. 17A and 17B show yet another variation of imaging hood
240 having at least two or more longitudinally positioned support
members 242 supporting the imaging hood membrane. The support
members 242 each have cross-support members 244 which extend
diagonally between and are pivotably attached to the support
members 242. Each of the cross-support members 244 may be pivotably
attached to one another where they intersect between the support
members 242. A jack or screw member 246 may be coupled to each
cross-support member 244 at this intersection point and a torquing
member, such as a torqueable wire 248, may be coupled to each jack
or screw member 246 and extend proximally through deployment
catheter 16 to outside the patient body. From outside the patient
body, the torqueable wires 248 may be torqued to turn the jack or
screw member 246 which in turn urges the cross-support members 244
to angle relative to one another and thereby urge the support
members 242 away from one another. Thus, the imaging hood 240 may
be transitioned from its low-profile, shown in FIG. 17A, to its
expanded profile, shown in FIG. 17B, and back into its low-profile
by torquing wires 248.
[0137] FIGS. 18A and 18B show yet another variation on the imaging
hood and its deployment. As shown, a distal portion of deployment
catheter 16 may have several pivoting members 250, e.g., two to
four sections, which form a tubular shape in its low profile
configuration, as shown in FIG. 18A. When pivoted radially about
deployment catheter 16, pivoting members 250 may open into a
deployed configuration having distensible or expanding membranes
252 extending over the gaps in-between the pivoting members 250, as
shown in FIG. 18B. The distensible membrane 252 may be attached to
the pivoting members 250 through various methods, e.g., adhesives,
such that when the pivoting members 250 are fully extended into a
conical shape, the pivoting members 250 and membrane 252 form a
conical shape for use as an imaging hood. The distensible membrane
252 may be made out of a porous material such as a mesh or PTFE or
out of a translucent or transparent polymer such as polyurethane,
PVC, Nylon, etc.
[0138] FIGS. 19A and 19B show yet another variation where the
distal portion of deployment catheter 16 may be fabricated from a
flexible metallic or polymeric material to form a radially
expanding hood 254. A plurality of slots 256 may be formed in a
uniform pattern over the distal portion of deployment catheter 16,
as shown in FIG. 19A. The slots 256 may be formed in a pattern such
that when the distal portion is urged radially open, utilizing any
of the methods described above, a radially expanded and
conically-shaped hood 254 may be formed by each of the slots 256
expanding into an opening, as shown in FIG. 19B. A distensible
membrane 258 may overlie the exterior surface or the interior
surface of the hood 254 to form a fluid-impermeable hood 254 such
that the hood 254 may be utilized as an imaging hood.
Alternatively, the distensible membrane 258 may alternatively be
formed in each opening 258 to form the fluid-impermeable hood 254.
Once the imaging procedure has been completed, hood 254 may be
retracted into its low-profile configuration.
[0139] Yet another configuration for the imaging hood may be seen
in FIGS. 20A and 20B where the imaging hood may be formed from a
plurality of overlapping hood members 260 which overlie one another
in an overlapping pattern. When expanded, each of the hood members
260 may extend radially outward relative to deployment catheter 16
to form a conically-shaped imaging hood, as shown in FIG. 20B.
Adjacent hood members 260 may overlap one another along an
overlapping interface 262 to form a fluid-retaining surface within
the imaging hood. Moreover, the hood members 260 may be made from
any number of biocompatible materials, e.g., Nitinol, stainless
steel, polymers, etc., which are sufficiently strong to optionally
retract surrounding tissue from the tissue region of interest.
[0140] FIG. 20C illustrates another variation of a hood 12 under
the present invention. In this variation, the hood 12 includes a
plurality of sections 264 that overlap on at least one side. The
overlapping sections 264 aid in conforming the distal end of the
hood against irregularly shaped tissue. The overlapping sections
264 may be affixed to the end of the hood 12. Alternatively, the
overlapping sections may extend a substantial length of the hood
(not shown). Any number of sections 264 may be used with the hood.
For example, when used against tissue having an irregular surface,
the device may include a large number of sections such that the end
of the hood 12 has a "brush-like" appearance. Alternatively, a
variation of the device may have fewer sections (as few as 2). Such
a variation may be appropriately configured for use against
relatively a smooth tissue surface. The sections 264 may be
fabricated from a polymer, cloth, or membrane filled structure.
Regardless of construction, the sections 264 improve conformation
of the hood against tissue.
[0141] Although it is generally desirable to have an imaging hood
contact against a tissue surface in a normal orientation, the
imaging hood may be alternatively configured to contact the tissue
surface at an acute angle. An imaging hood configured for such
contact against tissue may also be especially suitable for contact
against tissue surfaces having an unpredictable or uneven
anatomical geography. For instance, as shown in the variation of
FIG. 21A, deployment catheter 270 may have an imaging hood 272 that
is configured to be especially compliant. In this variation,
imaging hood 272 may be comprised of one or more sections 274 that
are configured to fold or collapse, e.g., by utilizing a pleated
surface. Thus, as shown in FIG. 21B, when imaging hood 272 is
contacted against uneven tissue surface T, sections 274 are able to
conform closely against the tissue. These sections 274 may be
individually collapsible by utilizing an accordion style
construction to allow conformation, e.g., to the trabeculae in the
heart or the uneven anatomy that may be found inside the various
body lumens.
[0142] In yet another alternative, FIG. 22A shows another variation
in which an imaging hood 282 is attached to deployment catheter
280. The contact lip or edge 284 may comprise one or more
electrical contacts 286 positioned circumferentially around contact
edge 284. The electrical contacts 286 may be configured to contact
the tissue and indicate affirmatively whether tissue contact was
achieved, e.g., by measuring the differential impedance between
blood and tissue. Alternatively, a processor, e.g., processor 98,
in electrical communication with contacts 286 may be configured to
determine what type of tissue is in contact with electrical
contacts 286. In yet another alternative, the processor 98 may be
configured to measure any electrical activity that may be occurring
in the underlying tissue, e.g., accessory pathways, for the
purposes of electrically mapping the cardiac tissue and
subsequently treating, as described below, any arrhythmias which
may be detected.
[0143] Another variation for ensuring contact between imaging hood
282 and the underlying tissue may be seen in FIG. 22B. This
variation may have an inflatable contact edge 288 around the
circumference of imaging hood 282. The inflatable contact edge 288
may be inflated with a fluid or gas through inflation lumen 289
when the imaging hood 282 is to be placed against a tissue surface
having an uneven or varied anatomy. The inflated circumferential
surface 288 may provide for continuous contact over the hood edge
by conforming against the tissue surface and facilitating imaging
fluid retention within hood 282.
[0144] Aside from the imaging hood, various instrumentation may be
utilized with the imaging and manipulation system. For instance,
after the field within imaging hood 12 has been cleared of the
opaque blood and the underlying tissue is visualized through the
clear fluid, blood may seep back into the imaging hood 12 and
obstruct the view. One method for automatically maintaining a clear
imaging field may utilize a transducer, e.g., an ultrasonic
transducer 290, positioned at the distal end of deployment catheter
within the imaging hood 12, as shown in FIG. 23. The transducer 290
may send an energy pulse 292 into the imaging hood 12 and wait to
detect back-scattered energy 294 reflected from debris or blood
within the imaging hood 12. If back-scattered energy is detected,
the pump may be actuated automatically to dispense more fluid into
the imaging hood until the debris or blood is no longer
detected.
[0145] Alternatively, one or more sensors 300 may be positioned on
the imaging hood 12 itself, as shown in FIG. 24A, to detect a
number of different parameters. For example, sensors 300 may be
configured to detect for the presence of oxygen in the surrounding
blood, blood and/or imaging fluid pressure, color of the fluid
within the imaging hood, etc. Fluid color may be particularly
useful in detecting the presence of blood within the imaging hood
12 by utilizing a reflective type sensor to detect back reflection
from blood. Any reflected light from blood which may be present
within imaging hood 12 may be optically or electrically transmitted
through deployment catheter 16 and to a red colored filter within
control electronics 118. Any red color which may be detected may
indicate the presence of blood and trigger a signal to the
physician or automatically actuate the pump to dispense more fluid
into the imaging hood 12 to clear the blood.
[0146] Alternative methods for detecting the presence of blood
within the hood 12 may include detecting transmitted light through
the imaging fluid within imaging hood 12. If a source of white
light, e.g., utilizing LEDs or optical fibers, is illuminated
inside imaging hood 12, the presence of blood may cause the color
red to be filtered through this fluid. The degree or intensity of
the red color detected may correspond to the amount of blood
present within imaging hood 12. A red color sensor can simply
comprise, in one variation, a phototransistor with a red
transmitting filter over it which can establish how much red light
is detected, which in turn can indicate the presence of blood
within imaging hood 12. Once blood is detected, the system may pump
more clearing fluid through and enable closed loop feedback control
of the clearing fluid pressure and flow level.
[0147] Any number of sensors may be positioned along the exterior
302 of imaging hood 12 or within the interior 304 of imaging hood
12 to detect parameters not only exteriorly to imaging hood 12 but
also within imaging hood 12. Such a configuration, as shown in FIG.
24B, may be particularly useful for automatically maintaining a
clear imaging field based upon physical parameters such as blood
pressure, as described above for FIGS. 10A and 10B.
[0148] Aside from sensors, one or more light emitting diodes (LEDs)
may be utilized to provide lighting within the imaging hood 12.
Although illumination may be provided by optical fibers routed
through deployment catheter 16, the use of LEDs over the imaging
hood 12 may eliminate the need for additional optical fibers for
providing illumination. The electrical wires connected to the one
or more LEDs may be routed through or over the hood 12 and along an
exterior surface or extruded within deployment catheter 16. One or
more LEDs may be positioned in a circumferential pattern 306 around
imaging hood 12, as shown in FIG. 25A, or in a linear longitudinal
pattern 308 along imaging hood 12, as shown in FIG. 25B. Other
patterns, such as a helical or spiral pattern, may also be
utilized. Alternatively, LEDs may be positioned along a support
member forming part of imaging hood 12.
[0149] In another alternative for illumination within imaging hood
12, a separate illumination tool 310 may be utilized, as shown in
FIG. 26A. An example of such a tool may comprise a flexible
intravascular delivery member 312 having a carrier member 314
pivotably connected 316 to a distal end of delivery member 312. One
or more LEDs 318 may be mounted along carrier member 314. In use,
delivery member 312 may be advanced through deployment catheter 16
until carrier member 314 is positioned within imaging hood 12. Once
within imaging hood 12, carrier member 314 may be pivoted in any
number of directions to facilitate or optimize the illumination
within the imaging hood 12, as shown in FIG. 26B.
[0150] In utilizing LEDs for illumination, whether positioned along
imaging hood 12 or along a separate instrument, the LEDs may
comprise a single LED color, e.g., white light. Alternatively, LEDs
of other colors, e.g., red, blue, yellow, etc., may be utilized
exclusively or in combination with white LEDs to provide for varied
illumination of the tissue or fluids being imaged. Alternatively,
sources of infrared or ultraviolet light may be employed to enable
imaging beneath the tissue surface or cause fluorescence of tissue
for use in system guidance, diagnosis, or therapy.
[0151] Aside from providing a visualization platform, the imaging
assembly may also be utilized to provide a therapeutic platform for
treating tissue being visualized. As shown in FIG. 27, deployment
catheter 320 may have imaging hood 322, as described above, and
fluid delivery lumen 324 and imaging lumen 326. In this variation,
a therapeutic tool such as needle 328 may be delivered through
fluid delivery lumen 324 or in another working lumen and advanced
through open area 332 for treating the tissue which is visualized.
In this instance, needle 328 may define one or several ports 330
for delivering drugs therethrough. Thus, once the appropriate
region of tissue has been imaged and located, needle 328 may be
advanced and pierced into the underlying tissue where a therapeutic
agent may be delivered through ports 330. Alternatively, needle 328
may be in electrical communication with a power source 334, e.g.,
radio-frequency, microwave, etc., for ablating the underlying
tissue area of interest.
[0152] FIG. 28 shows another alternative in which deployment
catheter 340 may have imaging hood 342 attached thereto, as above,
but with a therapeutic tool 344 in the configuration of a helical
tissue piercing device 344. Also shown and described above in FIGS.
7A and 7B for use in stabilizing the imaging hood relative to the
underlying tissue, the helical tissue piercing device 344 may also
be utilized to manipulate the tissue for a variety of therapeutic
procedures. The helical portion 346 may also define one or several
ports for delivery of therapeutic agents therethrough.
[0153] In yet another alternative, FIG. 29 shows a deployment
catheter 350 having an expandable imaging balloon 352 filled with,
e.g., saline 356. A therapeutic tool 344, as above, may be
translatable relative to balloon 352. To prevent the piercing
portion 346 of the tool from tearing balloon 352, a stop 354 may be
formed on balloon 352 to prevent the proximal passage of portion
346 past stop 354.
[0154] Alternative configurations for tools which may be delivered
through deployment catheter 16 for use in tissue manipulation
within imaging hood 12 are shown in FIGS. 30A and 30B. FIG. 30A
shows one variation of an angled instrument 360, such as a tissue
grasper, which may be configured to have an elongate shaft for
intravascular delivery through deployment catheter 16 with a distal
end which may be angled relative to its elongate shaft upon
deployment into imaging hood 12. The elongate shaft may be
configured to angle itself automatically, e.g., by the elongate
shaft being made at least partially from a shape memory alloy, or
upon actuation, e.g., by tensioning a pullwire. FIG. 30B shows
another configuration for an instrument 362 being configured to
reconfigure its distal portion into an off-axis configuration
within imaging hood 12. In either case, the instruments 360, 362
may be reconfigured into a low-profile shape upon withdrawing them
proximally back into deployment catheter 16.
[0155] Other instruments or tools that may be utilized with the
imaging system are shown in the side and end views of FIGS. 31A to
31C. FIG. 31A shows a probe 370 having a distal end effector 372,
which may be reconfigured from a low-profile shape to a curved
profile. The end effector 372 may be configured as an ablation
probe utilizing radio-frequency energy, microwave energy,
ultrasound energy, laser energy or even cryo-ablation.
Alternatively, the end effector 372 may have several electrodes
upon it for detecting or mapping electrical signals transmitted
through the underlying tissue.
[0156] In the case of an end effector 372 utilized for ablation of
the underlying tissue, an additional temperature sensor such as a
thermocouple or thermistor 374 positioned upon an elongate member
376 may be advanced into the imaging hood 12 adjacent to the distal
end effector 372 for contacting and monitoring a temperature of the
ablated tissue. FIG. 31B shows an example in the end view of one
configuration for the distal end effector 372 which may be simply
angled into a perpendicular configuration for contacting the
tissue. FIG. 31C shows another example where the end effector may
be reconfigured into a curved end effector 378 for increased tissue
contact.
[0157] FIGS. 32A and 32B show another variation of an ablation tool
utilized with an imaging hood 12 having an enclosed bottom portion.
In this variation, an ablation probe, such as a cryo-ablation probe
380 having a distal end effector 382, may be positioned through the
imaging hood 12 such that the end effector 382 is placed distally
of a transparent membrane or enclosure 384, as shown in the end
view of FIG. 32B. The shaft of probe 380 may pass through an
opening 386 defined through the membrane 384. In use, the clear
fluid may be pumped into imaging hood 12, as described above, and
the distal end effector 382 may be placed against a tissue region
to be ablated with the imaging hood 12 and the membrane 384
positioned atop or adjacent to the ablated tissue. In the case of
cryo-ablation, the imaging fluid may be warmed prior to dispensing
into the imaging hood 12 such that the tissue contacted by the
membrane 384 may be warmed during the cryo-ablation procedure. In
the case of thermal ablation, e.g., utilizing radio-frequency
energy, the fluid dispensed into the imaging hood 12 may be cooled
such that the tissue contacted by the membrane 384 and adjacent to
the ablation probe during the ablation procedure is likewise
cooled.
[0158] In either example described above, the imaging fluid may be
varied in its temperature to facilitate various procedures to be
performed upon the tissue. In other cases, the imaging fluid itself
may be altered to facilitate various procedures. For instance as
shown in FIG. 33A, a deployment catheter 16 and imaging hood 12 may
be advanced within a hollow body organ, such as a bladder filled
with urine 394, towards a lesion or tumor 392 on the bladder wall.
The imaging hood 12 may be placed entirely over the lesion 392, or
over a portion of the lesion. Once secured against the tissue wall
390, a cryo-fluid, i.e., a fluid which has been cooled to below
freezing temperatures of, e.g., water or blood, may be pumped into
the imaging hood 12 to cryo-ablate the lesion 390, as shown in FIG.
33B while avoiding the creation of ice on the instrument or surface
of tissue.
[0159] As the cryo-fluid leaks out of the imaging hood 12 and into
the organ, the fluid may be warmed naturally by the patient body
and ultimately removed. The cryo-fluid may be a colorless and
translucent fluid which enables visualization therethrough of the
underlying tissue. An example of such a fluid is Fluorinert.TM.
(3M, St. Paul, Minn.), which is a colorless and odorless
perfluorinated liquid. The use of a liquid such as Fluorinert.TM.
enables the cryo-ablation procedure without the formation of ice
within or outside of the imaging hood 12. Alternatively, rather
than utilizing cryo-ablation, hyperthermic treatments may also be
effected by heating the Fluorinert.TM. liquid to elevated
temperatures for ablating the lesion 392 within the imaging hood
12. Moreover, Fluorinert.TM. may be utilized in various other parts
of the body, such as within the heart.
[0160] FIG. 33C illustrates another variation of a system according
to the present invention. In this variation, an ultrasound beam 598
(for example, high frequency ultrasound, commonly referred to as
HIFU) transducer 600 is integrated into the hood 12 and/or catheter
16. The beam 598 focuses on a region of interest in the tissue.
This allows cauterization or welding of tissue via the ultrasound
beam. The clear solution assists the operator in focusing the beam
598 accurately on the target tissue surface. Optionally, a laser
pointer, LED or other pointing device/indicator 602 that coincides
with the focal point 604 of the beam 598 can be used as a guide to
ensure accurate placement of the beam 598 on the tissue
surface.
[0161] One possible application for this variation is treatment of
the PFO where the septum secundum is welded on to the septum primum
to achieve closure. Alternatively, by just injuring the septum
secundum with HIFU, the healing process can take over to close the
tissue onto the septum primum.
[0162] FIG. 34A shows another variation of an instrument which may
be utilized with the imaging system. In this variation, a laser
ring generator 400 may be passed through the deployment catheter 16
and partially into imaging hood 12. A laser ring generator 400 is
typically used to create a circular ring of laser energy 402 for
generating a conduction block around the pulmonary veins typically
in the treatment of atrial fibrillation. The circular ring of laser
energy 402 may be generated such that a diameter of the ring 402 is
contained within a diameter of the imaging hood 12 to allow for
tissue ablation directly upon tissue being imaged. Signals which
cause atrial fibrillation typically come from the entry area of the
pulmonary veins into the left atrium and treatments may sometimes
include delivering ablation energy to the ostia of the pulmonary
veins within the atrium. The ablated areas of the tissue may
produce a circular scar which blocks the impulses for atrial
fibrillation.
[0163] When using the laser energy to ablate the tissue of the
heart, it may be generally desirable to maintain the integrity and
health of the tissue overlying the surface while ablating the
underlying tissue. This may be accomplished, for example, by
cooling the imaging fluid to a temperature below the body
temperature of the patient but which is above the freezing point of
blood (e.g., 2.degree. C. to 35.degree. C.). The cooled imaging
fluid may thus maintain the surface tissue at the cooled fluid
temperature while the deeper underlying tissue remains at the
patient body temperature. When the laser energy (or other types of
energy such as radio frequency energy, microwave energy, ultrasound
energy, etc.) irradiates the tissue, both the cooled tissue surface
as well as the deeper underlying tissue will rise in temperature
uniformly. The deeper underlying tissue, which was maintained at
the body temperature, will increase to temperatures which are
sufficiently high to destroy the underlying tissue. Meanwhile, the
temperature of the cooled surface tissue will also rise but only to
temperatures that are near body temperature or slightly above.
[0164] Accordingly, as shown in FIG. 34B, one example for treatment
may include passing deployment catheter 16 across the atrial septum
AS and into the left atrium LA of the patient's heart H. Other
methods of accessing the left atrium LA may also be utilized. The
imaging hood 12 and laser ring generator 400 may be positioned
adjacent to or over one or more of the ostium OT of the pulmonary
veins PV and the laser generator 400 may ablate the tissue around
the ostium OT with the circular ring of laser energy 402 to create
a conduction block. Once one or more of the tissue around the
ostium OT have been ablated, the imaging hood 12 may be
reconfigured into a low profile for removal from the patient heart
H.
[0165] FIG. 34C also illustrates a variation of the system 10
having a visualization element 52 located at the end of the
catheter 16 and/or on the hood 12. The device 10 also includes a
fiber 606 coupled to a laser source 608. The fiber 606 is
optionally moveable so that the laser beam may be focused on
desired areas to treat tissue (e.g., the injury of the tissue leads
to healing over time). The fiber 606 can direct the laser energy
invarious patterns (e.g., spot treatment, rings, various
geometries, etc.). The laser may be collimated or non-collimated
(where a collimated laser beam will propagate with the lowest
possible beam divergence for a given beam size).
[0166] FIG. 34D illustrates another variation of a system according
to the present invention. In this variation, an inflatable member
520 the hood 12 to be expanded so that the device 10 may be
advanced and pushed against tissue. This variation prevents the
excessive use of saline or other fluid when the hood is not
properly or partially sealed against a tissue surface. The
inflatable member 520 may be fabricated to permit energy (e.g.,
such as laser or ultrasound as shown by line 521) to be transmitted
therethrough. For example, the inflatable member may be fabricated
from silicone and a low thermal conductivity liquid is used to
inflate the member 520.
[0167] One of the difficulties in treating tissue in or around the
ostium OT is the dynamic fluid flow of blood through the ostium OT.
The dynamic forces make cannulation or entry of the ostium OT
difficult. Thus, another variation on instruments or tools
utilizable with the imaging system is an extendible cannula 410
having a cannula lumen 412 defined therethrough, as shown in FIG.
35A. The extendible cannula 410 may generally comprise an elongate
tubular member which may be positioned within the deployment
catheter 16 during delivery and then projected distally through the
imaging hood 12 and optionally beyond, as shown in FIG. 35B.
[0168] In use, once the imaging hood 12 has been desirably
positioned relative to the tissue, e.g., as shown in FIG. 35C
outside the ostium OT of a pulmonary vein PV, the extendible
cannula 410 may be projected distally from the deployment catheter
16 while optionally imaging the tissue through the imaging hood 12,
as described above. The extendible cannula 410 may be projected
distally until its distal end is extended at least partially into
the ostium OT. Once in the ostium OT, an instrument or energy
ablation device may be extended through and out of the cannula
lumen 412 for treatment within the ostium OT. Upon completion of
the procedure, the cannula 410 may be withdrawn proximally and
removed from the patient body. The extendible cannula 410 may also
include an inflatable occlusion balloon at or near its distal end
to block the blood flow out of the PV to maintain a clear view of
the tissue region. Alternatively, the extendible cannula 410 may
define a lumen therethrough beyond the occlusion balloon to bypass
at least a portion of the blood that normally exits the pulmonary
vein PV by directing the blood through the cannula 410 to exit
proximal of the imaging hood.
[0169] Yet another variation for tool or instrument use may be seen
in the side and end views of FIGS. 36A and 36B. In this variation,
imaging hood 12 may have one or more tubular support members 420
integrated with the hood 12. Each of the tubular support members
420 may define an access lumen 422 through which one or more
instruments or tools may be delivered for treatment upon the
underlying tissue. One particular example is shown and described
above for FIG. 7C.
[0170] Various methods and instruments may be utilized for using or
facilitating the use of the system. For instance, one method may
include facilitating the initial delivery and placement of a device
into the patient's heart. In initially guiding the imaging assembly
within the heart chamber to, e.g., the mitral valve MV, a separate
guiding probe 430 may be utilized, as shown in FIGS. 37A and 37B.
Guiding probe 430 may, for example, comprise an optical fiber
through which a light source 434 may be used to illuminate a distal
tip portion 432. The tip portion 432 may be advanced into the heart
through, e.g., the coronary sinus CS, until the tip is positioned
adjacent to the mitral valve MV. The tip 432 may be illuminated, as
shown in FIG. 37A, and imaging assembly 10 may then be guided
towards the illuminated tip 432, which is visible from within the
atrial chamber, towards mitral valve MV.
[0171] Aside from the devices and methods described above, the
imaging system may be utilized to facilitate various other
procedures. Turning now to FIGS. 38A and 38B, the imaging hood of
the device in particular may be utilized. In this example, a
collapsible membrane or disk-shaped member 440 may be temporarily
secured around the contact edge or lip of imaging hood 12. During
intravascular delivery, the imaging hood 12 and the attached member
440 may both be in a collapsed configuration to maintain a low
profile for delivery. Upon deployment, both the imaging hood 12 and
the member 440 may extend into their expanded configurations.
[0172] The disk-shaped member 440 may be comprised of a variety of
materials depending upon the application. For instance, member 440
may be fabricated from a porous polymeric material infused with a
drug eluting medicament 442 for implantation against a tissue
surface for slow infusion of the medicament into the underlying
tissue. Alternatively, the member 440 may be fabricated from a
non-porous material, e.g., metal or polymer, for implantation and
closure of a wound or over a cavity to prevent fluid leakage. In
yet another alternative, the member 440 may be made from a
distensible material which is secured to imaging hood 12 in an
expanded condition. Once implanted or secured on a tissue surface
or wound, the expanded member 440 may be released from imaging hood
12. Upon release, the expanded member 440 may shrink to a smaller
size while approximating the attached underlying tissue, e.g., to
close a wound or opening.
[0173] One method for securing the disk-shaped member 440 to a
tissue surface may include a plurality of tissue anchors 444, e.g.,
barbs, hooks, projections, etc., which are attached to a surface of
the member 440. Other methods of attachments may include adhesives,
suturing, etc. In use, as shown in FIGS. 39A to 39C, the imaging
hood 12 may be deployed in its expanded configuration with member
440 attached thereto with the plurality of tissue anchors 444
projecting distally. The tissue anchors 444 may be urged into a
tissue region to be treated 446, as seen in FIG. 39A, until the
anchors 444 are secured in the tissue and member 440 is positioned
directly against the tissue, as shown in FIG. 39B. A pullwire may
be actuated to release the member 440 from the imaging hood 12 and
deployment catheter 16 may be withdrawn proximally to leave member
440 secured against the tissue 446.
[0174] Another variation for tissue manipulation and treatment may
be seen in the variation of FIG. 40A, which illustrates an imaging
hood 12 having a deployable anchor assembly 450 attached to the
tissue contact edge 22. FIG. 40B illustrates the anchor assembly
450 detached from the imaging hood 12 for clarity. The anchor
assembly 450 may be seen as having a plurality of discrete tissue
anchors 456, e.g., barbs, hooks, projections, etc., each having a
suture retaining end, e.g., an eyelet or opening 458 in a proximal
end of the anchors 456. A suture member or wire 452 may be
slidingly connected to each anchor 456 through the openings 458 and
through a cinching element 454, which may be configured to slide
uni-directionally over the suture or wire 452 to approximate each
of the anchors 456 towards one another. Each of the anchors 456 may
be temporarily attached to the imaging hood 12 through a variety of
methods. For instance, a pullwire or retaining wire may hold each
of the anchors within a receiving ring around the circumference of
the imaging hood 12. When the anchors 456 are released, the
pullwire or retaining wire may be tensioned from its proximal end
outside the patient body to thereby free the anchors 456 from the
imaging hood 12.
[0175] One example for use of the anchor assembly 450 is shown in
FIGS. 41A to 41D for closure of an opening or wound 460, e.g.,
patent foramen ovale (PFO). The deployment catheter 16 and imaging
hood 12 may be delivered intravascularly into, e.g., a patient
heart. As the imaging hood 12 is deployed into its expanded
configuration, the imaging hood 12 may be positioned adjacent to
the opening or wound 460, as shown in FIG. 41A. With the anchor
assembly 450 positioned upon the expanded imaging hood 12,
deployment catheter 16 may be directed to urge the contact edge of
imaging hood 12 and anchor assembly 450 into the region surrounding
the tissue opening 460, as shown in FIG. 41B. Once the anchor
assembly 450 has been secured within the surrounding tissue, the
anchors may be released from imaging hood 12 leaving the anchor
assembly 450 and suture member 452 trailing from the anchors, as
shown in FIG. 41C. The suture or wire member 452 may be tightened
by pulling it proximally from outside the patient body to
approximate the anchors of anchor assembly 450 towards one another
in a purse-string manner to close the tissue opening 462, as shown
in FIG. 41D. The cinching element 454 may also be pushed distally
over the suture or wire member 452 to prevent the approximated
anchor assembly 450 from loosening or widening.
[0176] FIG. 41E illustrates a tissue imaging and manipulation
assembly 10 configured to deliver an implant 464. In this
variation, the implant comprises a shaft having a plurality of
thrombogenic fibers 466. The implant 464 further includes a tissue
attachment member 468. In use, the assembly 10 delivers the implant
464 to a tissue area or cavity. The implant may be rotated into
tissue (or otherwise attached) using the attachment member 468. The
implant 464 may be combined with other procedures discussed herein,
especially where occlusion of a cavity or opening is required.
[0177] FIG. 41F illustrates another variation of an assembly 10
according to the present invention. In this case, the implant 474
may comprise a stent, coil, patch, suture, or other such implant.
The implant 474 may be delivered using a delivery catheter 473 or
similar means.
[0178] Another example for an alternative use is shown in FIG. 42,
where the deployment catheter 16 and deployed imaging hood 12 may
be positioned within a patient body for drawing blood 472 into
deployment catheter 16. The drawn blood 472 may be pumped through a
dialysis unit 470 located externally of the patient body for
filtering the drawn blood 472 and the filtered blood may be
reintroduced back into the patient.
[0179] Yet another variation is shown in FIGS. 43A and 43B, which
show a variation of the deployment catheter 480 having a first
deployable hood 482 and a second deployable hood 484 positioned
distal to the first hood 482. The deployment catheter 480 may also
have a side-viewing imaging element 486 positioned between the
first and second hoods 482, 484 along the length of the deployment
catheter 480. In use, such a device may be introduced through a
lumen 488 of a vessel VS, where one or both hoods 482, 484 may be
expanded to gently contact the surrounding walls of vessel VS. Once
hoods 482, 484 have been expanded, the clear imaging fluid may be
pumped in the space defined between the hoods 482, 484 to displace
any blood and to create an imaging space 490, as shown in FIG. 43B.
With the clear fluid in-between hoods 482, 484, the imaging element
486 may be used to view the surrounding tissue surface contained
between hoods 482, 484. Other instruments or tools may be passed
through deployment catheter 480 and through one or more openings
defined along the catheter 480 for additionally performing
therapeutic procedures upon the vessel wall.
[0180] FIG. 43C illustrates another variation of a deployment
catheter 480 having a series of deployable hoods 482, 484 spaced
close together. The deployment catheter 480 will include at least
two fluid supply lumens 476, 478, where each lumen is fluidly
coupled to an open area within the outer 482 and inner 484 hoods.
During use, the fluid running between the outer and inner hoods
482, 484 clears the blood, debris or other obstructions from around
the inside hood 484. One benefit is that this allows the device to
have better visualization within the inner hood 484 by preventing
bodily fluids from entering the open area. This is especially
useful when the inner hood 484 abuts tissue and fluid from the
outer hood 482 creates a flow pattern that opposes bodily fluids
from entering the open area of the inner hood 484.
[0181] Visualization elements may be placed within one or both
hoods. In one variation of the device, the inner hood 484 may be
fabricated from a clear material so that one or more visualization
elements may be placed within the outer hood 482. Alternatively, or
in combination, the visualization elements may be placed to
visualize tile open area of the inner hood 484. It should be noted
that any number of hoods may be used.
[0182] Another variation of a deployment catheter 500 which may be
used for imaging tissue to the side of the instrument may be seen
in FIGS. 44A to 45B. FIGS. 44A and 44B show side and end views of
deployment catheter 500 having a side-imaging balloon 502 in an
un-inflated low-profile configuration. A side-imaging element 504
may be positioned within a distal portion of the catheter 500 where
the balloon 502 is disposed. When balloon 502 is inflated, it may
expand radially to contact the surrounding tissue, but where the
imaging element 504 is located, a visualization field 506 may be
created by the balloon 502, as shown in the side, top, and end
views of FIGS. 45A to 45B, respectively. The visualization field
506 may simply be a cavity or channel which is defined within the
inflated balloon 502 such that the visualization element 504 is
provided an image of the area within field 506 which is clear and
unobstructed by balloon 502.
[0183] In use, deployment catheter 500 may be advanced
intravascularly through vessel lumen 488 towards a lesion or tumor
508 to be visualized and/or treated. Upon reaching the lesion 508,
deployment catheter 500 may be positioned adjacently to the lesion
508 and balloon 502 may be inflated such that the lesion 508 is
contained within the visualization field 506. Once balloon 502 is
fully inflated and in contact against the vessel wall, clear fluid
may be pumped into visualization field 506 through deployment
catheter 500 to displace any blood or opaque fluids from the field
506, as shown in the side and end views of FIGS. 46A and 46B,
respectively. The lesion 508 may then be visually inspected and
treated by passing any number of instruments through deployment
catheter 500 and into field 506.
[0184] FIGS. 47A-47B illustrate a variation of a device according
to the present invention where components of the system 560 allow
for dissection/blunt dissection of tissue. As shown, a hood 564
extends from a catheter 562, where the hood 564 comprises a
plurality of rigid sections 566 or leaflets. The leaflets 566, 568,
570 may be fabricated from a stiff metal or polymer. Moreover, a
variation of the device may include leaflets 566, 568, 570 having
alternating constructions (e.g., a flexible leaflet interspaced
between stiff leaflets, a soft leaflet interspaced between stiff or
hard leaflets, etc.) Although the leaflets are illustrated as
having tapered profiles towards a tip 572 of the device 560, the
tip 572 of the device may be sufficiently blunted so as to avoid
unnecessary trauma to the tissue.
[0185] FIG. 47A illustrates the device 560 as it approaches
adjacent layers of tissue 2, 4. As illustrated in FIG. 47B, once
appropriately positioned, the device 560 dissects tissue by opening
or repeatedly opening and closing to separate the layers of tissue
2, 4. FIG. 47B also illustrates the dissector hood 564 as having a
flexible material or webbing 576 located between adjacent leaflets
566, 568, 570. This flexible material/webbing 576 permits the hood
to form a seal once the hood is placed adjacent to a tissue
surface. As illustrated, the leaflets 566, 568, 570 may overlap (as
shown by the overlapping portion 569).
[0186] FIG. 48A illustrates a variation of a tissue imaging and
manipulation assembly 10 further including an elongate bypass
portion 580. The elongate bypass portion 580 includes at least one
bypass lumen 582 that allows a fluid path between proximal opening
584 in the catheter 16 and a distal opening 586 located distally of
the hood 16. The bypass lumen 582 allows fluid to pass around the
open area during a surgical procedure. Furthermore, the hood 12 may
include one or more visualization element 52 to allow visualization
of the open area. A variation of the assembly 10 may include a
pump-type device 578 to assist in moving fluid through the assembly
10.
[0187] The elongate bypass portion 580 may be moveable relative to
the hood 12 or catheter 16. In addition, the elongate bypass
portion 580 may include one or more structures to facilitate
various procedures. For example, FIG. 48B illustrates a variation
of the system 10 of FIG. 48A with the addition of a support flap
588. The support flap 588 is preferably fabricated from a material
that allows the flap 588 to assume a reduced profile for delivery.
Upon expansion, the flap 588 provides a semi-rigid support when
placed against tissue. In one application of this configuration,
the assembly 10 may be passed through a valve (e.g., a mitral
valve), such that the hood 12 creates a first open area over the
valve. The flap 588 may then support the distal surface of the
valve. Accordingly, devices may be advanced through the catheter 16
and to within the open area to perform surgical repair of the
valve. In an additional variation, the region between proximal
openings 584 and the distal end of the catheter 586 contains a
valve (e.g., a one-way valve) to control the flow of fluid (in the
case of a one-way valve fluid would only flow in a single
direction).
[0188] FIG. 48C illustrates a cross-sectional view of the flap 588
placed against a distal surface of tissue (or a valve). As shown,
the hood 16 creates an open area over the tissue so that devices
592 may be advanced through the catheter 16 to repair or treat the
tissue. As discussed above, the elongate portion 580 may be
withdrawn relative to the catheter 16 to secure the tissue between
the hood 12 and flap 588. FIG. 48C also illustrates a variation of
an assembly 10 where the elongate portion 580 further includes a
tissue attachment member 590. In this variation, the tissue
attachment member 590 comprises a helical member.
[0189] FIG. 48D illustrates a variation of an assembly 10 according
to the present invention where the expanded hood 12 is off-center
relative to the catheter 16. Variations include assemblies where
the elongate portion 580 is also be off-center relative to the hood
12 when expanded. The visualization element 52 may be placed on a
side of the hood 12 to give optimal viewing of the open area.
However, the invention also contemplates placement of one or more
visualization elements at any location and on any structure within
the open area. It is also contemplated that variations of the
assembly with an off-set hood configuration, such as that shown in
FIG. 48D, may or may not incorporate a support flap as shown in
FIGS. 48A-48C.
[0190] FIG. 48E illustrates another variation of an assembly 10
with an elongate portion 580. In this variation, the elongate
portion 580 supplies fluid that is ultimately evacuated through the
catheter 16. As shown, as the fluid enters the target site via the
elongate portion 580 the hood 12 prevents the fluid from escaping
beyond the open area. A lumen in fluid communication with the open
area evacuates the fluid and may also aspirate blood located in the
left atrial appendage LAA. Such a variation is useful for work in
the left atrial appendage LAA. A variation of the assembly 10 may
include a tissue attachment member 590 to stabilize the assembly 10
at the target site. In use, the device is advanced through the
right atrium RA through the heart wall and into the left atrial
appendage LAA in the left atrium LA. The tissue attachment member
590 may be rotated into the tissue to secure the hood 12 and
elongate member 580 within the appendage LAA. As noted above, the
elongate member 580 may be moveable relative to the catheter 16 and
hood 12. Accordingly, pulling the elongate member 580 when the
tissue attachment member 590 is coupled to tissue could assist in
creating a compressive force between the hood 12 and the opening of
the appendage LAA.
[0191] FIG. 48F illustrates another variation of tissue imaging and
manipulation assembly 10. In this variation, the assembly 10
includes an elongate member 580 having 10 a balloon 594 coupled to
a balloon lumen 596. The balloon 594 may function as an occlusion
balloon. As such, the elongate member 580 may be configured to
permit passage of a guidewire or other guiding means. The elongate
portion 580 may also be configured to have a bypass lumen as shown
in FIG. 48A to allow fluid to move from an area proximally to the
hood 12 to an area distally of the balloon.
[0192] FIG. 49A-49E illustrate the use of an elongate member 528
having a plurality of openings 530. FIG. 49A shows an elongate
member 528 and openings 530 that act as an irrigator/aspirator to
circulate fluid between the catheter 16 and open area of the hood
12. The elongate member may have a tissue attaching member, as
discussed herein, attached to a distal end. Moreover, the catheter
may have a flow distributor 532 to encourage laminar flow of fluid.
Although not illustrated, a pump may be used in any of the
described systems to allow the elongate member 528 or catheter 16
to aspirate fluid out of the open area of the hood 12. In
variations of the assembly 10, the elongate member 528 may move in
and out of the catheter. It should be noted that in any of the
variations discussed herein, the flow of fluid may be the reverse
of that shown. In such cases, the hood or other structure may
require a slight structural change to handle any vacuum forces.
[0193] FIG. 49B illustrates another variation of an assembly 10. In
this variation, the hood 12 comprises a double layer with a
plurality of openings 534 in the interior layer. Accordingly, fluid
passes from the catheter 16 into the hood 12 and out of the
openings 534. Again, the elongate member 528 draws fluid from
within the open area of the hood 12. FIG. 49C illustrates a similar
assembly to 49B. However, in this variation, the base of the hood
12 contains the openings 534 that provide fluid into the open area
of the hood 12. Fluid returns through the catheter 16.
[0194] FIG. 49D illustrates another variation of a hood 12 under
the present invention. In this variation, the hood 12 includes a
plurality of elongate members 528 each having openings 530 that
allow for circulation of fluid. One or more of the elongate members
528 are attached to the surface of the hood while a separate
elongate member 528 extends through the catheter 16. FIG. 49E
illustrates a similar variation where two elongate members 528
extend through the catheter 16 rather than being attached to the
hood.
[0195] FIGS. 50A-50C illustrate variations of a tissue imaging and
manipulation assembly 10 designed to translate or "walk" across
tissue surfaces when inserted within the body. In a first
variation, the assembly 10 includes an outer sheath 536 having an
articulating section or joint 538 allowing for at least one degree
of motion. The assembly further includes a catheter 16 being
axially moveable, as shown by arrows 540, relative to the sheath
536. The catheter 16 may further include a second joint 542 that
allows for angular rotation of the hood 12, as shown by arrows 544.
Accordingly, the joints of the assembly 10 allow for repositioning
of the hood 12 as it sweeps or walks across tissue.
[0196] FIG. 50B illustrates another variation of a tissue imaging
and manipulation assembly 10 designed to translate or "walk" across
tissue surfaces. In this variation, one or more "fingers" 546, 548
are moveably located within the hood 12. Each finger 546, 548 is
designed to move axially relative to the hood 12, as illustrated by
arrows 550, as well as angularly relative to the hood 12, as
illustrated by arrows 552. Accordingly, as one finger extends
beyond the hood 12, the finger 548 raises it off of the tissue
surface, as shown in FIG. 50C. Once raised off of the tissue, the
second finger 546 advances in the desired direction and extends to
contact tissue as the first finger 548 retracts. Thus, this walking
motion of the fingers allows for precise movement of the hood
across tissue.
[0197] The user controls to actuate and control movement are not
illustrated but may be those controls conventionally used by
medical practitioner. Alternatively, the assembly 10 may be coupled
to a robotic manipulation system as described above.
[0198] The applications of the disclosed invention discussed above
are not limited to certain treatments or regions of the body, but
may include any number of other treatments and areas of the body.
Modification of the above-described methods and devices for
carrying out the invention, and variations of aspects of the
invention that are obvious to those of skill in the arts are
intended to be within the scope of this disclosure. Moreover,
various combinations of aspects between examples are also
contemplated and are considered to be within the scope of this
disclosure as well.
* * * * *